Improvements in and relating to the Treatment of Paper Making Fibre Materials.
Year: 1890

page_text: Date of Application, 30th Apr., 1890
Complete Specification Left, 29th Jan., 1891-Accepted, 18th Apr., 1891
TRUVIDIUNAL DEVITRATION.
Improvements in and relating to the Treatment of Paper Making
Fibre Materials.
We, JAMES JOHNSTON, of Peter-Culter, in the County of Aberdeen, and
GEORGE JOHNSTON, of St. Cuthbert's Paper Works, Wells, in the County of
Somerset, Paper Manufacturers, do hereby declare the nature of our invention to
be as follows:-
This invention has reference to and comprises a new or improved treatment of
esparto grass and other fibre materials for making paper in the steam boilers
presently employed for treating these under steam pressure with strong alkalies,
and after the fibre has been so treated as usual, and the strong and second lyes
have been run off from the fibre and boilers, and the steam shut off, although it
might be in separate boilers after removal from these for the new treatment, which
will have the effect of saving much time and fibre in the subsequent processes and
treatment of said fibrous material.
The nature and novelty of the new process or improvement consist in introducing
into the boilers, after the steam has been shut off and the second lyes have been
removed, strong currents of cold pressure air from air forcing pumps or engines up
through the fibre material, as also a current of cold water from a force pump, or it
might be a head pressure of water, both so as to circulate through and agitate the
material, until it was thoroughly cleaned, and oxidise the fibre and wash off all the
weak alkalies with the water, which would be introduced and allowed to flow off* in
a regular stream, or from time to time as desired and found best, and either allowed
to escape to waste or be forced up into a tank for subsequent use in the boilers.
The upper part of the boiler would also be fitted with a special air pipe and cock
opened to the atmosphere to allow of the relief of pressure and escape of the
agitating air from above, first forced in preferably below the perforated bottom, to
spread the air and circulate the water as the steam is at present spread up through
the fibre. After this treatment the fibre would be removed for subsequent bleaching,
und treatment in the rag engines, to form the paper pulp, all otherwise substantially
as heretofore.
Although this new treatment of circulating water and air through the material
has been described as performed in the usual steam pressure boilers after the
removal of the strong alkalies, it is to be understood that the fibre material may be
removed after being treated therein to a separate vessel, and there receive the new
air and water agitating washing treatment; and although the agitation of the
fibre material has been described as effected in the process by the circulation of
the air and water through the fibre, it is to be understood that the agitation may
be wholly or partially performed by rotating screw vanes or other mechanical
agitators.
Dated the 20th A 1900

page_text: COMPLETE SPECIFICATION.
Improvements in and relating to the Treatment of Paper Making
Fibre Materials.
We, JAMES JOnxsros, of Peter-Culter, in the County of Aberdeen, and
GEORGE JOHNSTON, of St. Cuthbert's Paper Works, Wells, in the County of
Somerset, Paper Manufacturers, do hereby declare the nature of our invention,
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement in writing, that is to say:
Our invention has reference to and comprises a new or improved treatment of
esparto grass and other fibre materials for making paper in the steam boilers
presently employed for treating these under steam pressure with strong alkalies,
and after the fibre has been so treated as usual, and the strong and second lyes
have been run off from the fibre and boiler, and the steam shut off, although it
might be in separate boilers after removal from these for the new treatment, which
will have the effect of saving much time and fibre in the subsequent processes and
treatment of said fibrous material,
The nature and novelty of the new process or improvements consist in introducing
into the boilers, after the steam has been shut off and the seronil lyes have been
removed, and the boiler has been filled up with cold water, strong currents of cold
pressure air from air forcing pumps or engines, up through the fibre material, so us
io eirendats through and agitate the material, until it was thoroughly cleaned, and
oxidise the fibre siul wash off all the weak alkalies with the water, which would be
drawn or blown off from time to time as desired and found bet, und either allowed
to escape to waste or he forced up into a tank for subsequent use in the boilers.
The upper part of the boiler would also be fitted with a special nir pipe and cock
opened to the atmosphere to allow of the relief of pressure and escape of the
agitating air from above, first forced in preferably below the perforated bottom, to
spread the air and circulate the water as the steam is at present spread up through
the fibre. After this treatment the fibre would be removed for subsequent fleaching.
and treatment in the rag engines, to form the paper pulp all otherwise substantially
as heretofore.
And in order that our said invention and the manner of performing or carrying
our new system into gluet or practice may be properly understood, we have here-
unto appended an explanatory sheet of drawings in which Figure 1 is an elevation
showing an ordinary esparto grass or paper fibre high pressure boiler in sectional
elevation, as taken on the line 2-2 in Figure 2 and its liquor, steam, and water
pipe fittings to which is applied or new system and improvements of treating the
paper fibre with compressed air or air and water in addition to the ordinary
treatment as hereinafter described. And Figure 2 is a horizontal section one-half
of which is taken above the top rose" eirenlating pipes and the other half
taken below the false perforated bottom A both on the irregular fine 1--1 in
Figure 1.
"
Referring to these drawings is the shell of the ordinary esparto grass or
paper fibre boiler formed of sheet iron or steel, and A'A" are the domed or
capped top and bottom, and A the open top and lid for inserting the esparto grass
or other fibre to be treated, and As the door and lid for discharging or removing
the esparto grass or fibre after being treated within the boiler. A is the perforated
bottom made of radial plates supported some distance up from the bottom A",
leaving a space A, between these for the circulating of the water and alkali
liquor. B is a stand branch pipe for feeding in through a branch stool and rose B', B",
and top A¹ of boiler A, either alkali liquor, or cold water, by the pipe and its
cocks or valves C', C", and branches (from separate overhead tanks or cisterns,
one of which, the hot water one W, is shown in front of the other two in Figure 1,
and from which the hot water is supplied by the pipe D,and its cocks or valves B,D",

page_text: and branches D, or it might be the weak after liquor washings, also supplied to
this cistern W by the uptake pipe F as hereinafter stated. E is a blow off steam
pipe with cock or valve E, for blowing off the steam when that is desired down
into the cistern W. e is the escape reducing pressure small steam pipe fitted with
regulating valve and leading the steam from the top of the stand pipe 13 down
into the said cistern W, all as indicated by the arrows on these pipes. G is the
steam pipe from a boiler fitted with stop valve G', for leading the steam by the
T branch G and pipe G' down to and up the centre cross branch G³ of a duplex
annular chambered box (4 bolted to a stool on the centre of the bottom A" of the
boiler A. The steam thus admitted from the four cross branches G by short
continuations G, is led into the wide open mouths g of the curved lower knees
of the four uptake water circulating pipes,,, the two of which are
connected at top to large semi-circular rose pipes, and the other two gg, at
right angles to the first pair are connected to a complete circular rose pipe g³
close under the domed top A of the boiler A, all clear of the door A², for filling
in the esparto grass fibre.
y
The operation of treating the esparto grass in these high pressure boilers is to
fill the vessel half full or so with the prepared alkali liquor fed from an overhead
cistern by the pipe C. The steam, at about 45 pounds pressure, is then turned on
by the pipe G and stop valve G, and the esparto grass fibre fed in through the
top door A, the steam heating and circulating the liquor up through the pipes,,
and top rose pipes, to completely saturate, and soften and lower the fibre in
the vessel, when the vessel is filled with more fibre aud the lid bolted down, when
full pressure is put on and the fibre treated with the hot circulating liquor for
about two hours. The steam is then shut off and the fibre allowed to stand under
the action of the liquor for about two hours, until the pressure has fallen to about
20 pounds by the escape through the regulating pipe and tape e'. The liquor is
then blown off through the annular chamber (surrounding the steam branch G³,
into the lateral branch and pipe F, F", and cock F2 to a pipe at F, leading to any
receiving tank or cistern for subsequent treatment in recovering the alkulies. This
cock is then shut off, and the boiler A filled with hot water by the pipe and
taps D. D', D", and a little live steam again put on for about half an hour, when
this weak solution of refuse washings is blown off through the pipe F, F", and
cock by the pipe F's preferably to the same tank as the strong liquor was
previously blown into. The boiler is then filled with cold water from a cold water
overhead cistern, or it might be a pump, by the branch C, and pipe and tap C, C
and by our improvements cold compressed air is led by the pipe a and cock or
valve a, from an air compressing engine b, b', or it might be other air blower or
fan, and which may have an air accumulator between the compressing cylinder
and the pipe a, and the air preferably at about 45 pounds pressure is led as
indicated by the arrows into the T branch down the pipe G to circulate the
cold water up through circulating pipes and rose pipes, and down through
the esparto grass fibre and perforated bottom A, a portion of the pressure air
being allowed to escape up through the regulating cock and pipe e, el, to cause a
variation of pressure and ensure the circulation of the water, and this treatment is
continued for about an hour when the water is then run or blown off through the
pipes F, and up the pipe F, to a cistern, or off through the pipe and cock F, F
to waste. This new washing treatment is again repeated by filling the boiler A
with cold water again and putting on the air pressure by the pipe u, and circulation
of the cold water for about another hour, when this washing water is blown off
for subsequent use or to waste as before described. And this new washing, cooling,
and circulating treatment with water and compressed air can be repeated as many
times as desired to get the esparto grass fibre thoroughly cleaned before being
removed from the boiler A, by the door A³ to be bleached or pulped.
Although this new treatment of circulating cold water and compressed air
through the material has been described, and shown, as performed in the usual
steam pressure boilers after the removal of the strong alkalies, it is to be understood

page_text: that the fibre material may be removed after being treated in the usual manner
therein with alkalies and steam and hot water, to a separate vessel, and there
receive the new air and cold water agitating washing treatment described; and
although the agitation of the fibre material has been described as effected in the
process by the circulation of the air and water through the fibre, it is to be under-
stood that the agitation may be wholly or partially performed, in combination with
the air and water, by rotating screw vanes or other mechanical agitators.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
clain is :-
First. The herein described process or system of cleansing or treating esparto
grass or other paper-making libre materials, consisting in treating these with
compressed air and circulating cold water or liquid after the first treatment and
strong and second lyes have been run off from the fibre and boiler, substantially as
and in the manner set forth in reference to and by way of application shown in the
accompanying drawings.
Second. In a system or process for cleansing or treating esparto grass or other
paper-making fibre materials within a close boiler or vessel, the use of compressed
air in rumbiuntion with cold water or liquid, substantially as and in the manner
herein described in reference to and by way of application shown in the accompanying
drawings.
Dat the gil Januarv 1801
W. R. M. THOMSON & Co.,
96, Buchanan Street, Glasgow, Agents.