AN IMPROVED MODE OF AND APPARATUS FOR BLEACHING AND DRAINING ESPARTO PROVISIONAL SPATION FI AND OTHER MATERIAL EMPLOYED IN THE MANUFACTURE OF PAPER
Year: 1871

page_text: LETTERS PATENT to John Torrance and Thomas Torrance, both of
Bitton, in the County of Gloucester, for the Invention of "AN
IMPROVED MODE OF AND APPARATUS FOR BLEACHING AND DRAINING ESPARTO
PROVISIONAL SPECIFICATION left by the said John Torrance and
Thomas Torrance at the Office of the Commissioners of Patents,
with their Petition, on the 13th July 1871.
We, JOHN TORRANCE and THOMAS TORRANCE, both of Bitton, in the
County of Gloucester, do hereby declare the nature of the said Inven-
tion for "AN IMPROVED MODE OF AND APPARATUS FOR BLEACHING AND DRAINING
ESPARTO FIBRE AND OTHER MATERIAL EMPLOYED IN THE MANUFACTURE OF PAPER,"
to be as follows:-
-
The Invention comprises bleaching by the application or assistance of
an agitator for thoroughly stirring up the pulp or material during the
bleaching process, and in a vat or vessel into which the pulp or material

page_text: and the bleaching fluid are placed or are passed from the pulping or
breaking in engine; and draining by means of a centrifugal drainer.
The manner in which the Invention is to be performed is as follows,
but we do not desire to limit ourselves to precise details:-In one set of
apparatus we employ two ordinary or approved pulping or breaking-in
engines, four bleaching vats with agitators in each, and each of
capacity corresponding to two pulping engines, and further we employ
one centrifugal drainer. We add the bleaching liquor to stuff while in
pulping engine, or after leaving same, or partly before and partly after.
The several parts of the complete apparatus are so placed that the
material may flow or pass by pipes from pulping engines to vats, and
thence to drainer. When drained water can be put into drainer by
pipe for washing remnant of liquor out of half stuff if required,
agitators in vats work on or are carried and driven by horizontal or
vertical spindles. Vats are furnished with waste pipes. Centrifugal
drainer works on or is carried and driven by a vertical axis, its sides
being constructed of perforated metal plates or wire gauze. Valves or
sluices are provided at bottom with handles for opening them and
discharging the drained pulp. And a box or case round the drainer
receives the liquor which passes off by a pipe provided for the purpose.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Torrance and Thomas Torrance in the
Great Seal Patent Office on the 13th January 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JOHN
TORRANCE and THOMAS TORRANCE, both of Bitton, in the County of
Gloucester, send greeting.
1
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirteenth day of July, in the year
of our Lord One thousand eight hundred and seventy-one, in the thirty-
fourth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto us, the said John Torrance and Thomas Torrance,
Her special licence that we, the said John Torrance and Thomas
Torrance, our executors, administrators, and assigns, or such others as
we, the said John Torrance and Thomas Torrance, our executors,
administrators, and assigns, should at any time agree with, and no others,..

page_text: 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 Ohannel
Islands, and Isle of Man, an Invention for "AN IMPROVED MODE OF AND
APPARATUS FOR BLEACHING AND DRAINING ESPARTO FIBRE AND OTHER MATERIAL
EMPLOYED IN THE MANUFACTURE OF PAPER," upon the condition (amongst
others) that we, the said John Torrance and Thomas Torrance, our
executors or administrators, by an instrument in writing under our, 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 we, the said John Torrance and Thomas
Torrance, do hereby declare the nature of our said Invention, and
in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
The Invention comprises, firstly, bleaching by the application or
assistance of an agitator for mechanically stirring up the pulp or
material during the bleaching process, and in a vat or vessel into which
the pulp or material and the bleaching fluid are placed or are passed
from the pulping or breaking-in engine.
And, secondly, draining by means of a centrifugal drainer.
The manner in which the Invention is to be performed is as follows,
but we do not desire to limit ourselves to precise details :-In one set of
apparatus we employ two ordinary or approved pulping or breaking-in
engines, four bleaching vats with agitators in each, and each of capacity
corresponding to two pulping engines, and, further, we employ one cen-
trifugal drainer. We add the bleaching liquor to stuff while in pulping
engines or after leaving them, or partly before and partly after leaving
them. The several parts of the complete apparatus are so placed that
the material may flow or pass by pipes from the pulping engines to the
vats and thence to the drainer. The agitators in the vats work on or
are carried and driven by horizontal or vertical spindles. The vats are
furnished with waste pipes. The centrifugal drainer works on or is
carried and driven by a vertical axis, its sides being constructed of per-
forated metal plates or wire gauze, valves or sluices are provided at
bottom with handles for opening them and discharging the drained pulp,

page_text: .
And a box or case round the drainer receives the liquor which passes off
by a pipe provided for that purpose.
In further illustration of the manner in which the said Invention
is to be performed, we will proceed to describe the accompanying
illustrative Drawing exhibiting the arrangement and construction (as t
actually in use) of one complete set of the improved apparatus for
carrying on the bleaching and draining processes.
Figure 1 shews the four bleaching vats and one centrifugal drainer
in relative position, the second vat being represented in elevation (with
driving gear in front), the third being represented in vertical section
parts only of the first and fourth being indicated and the centrifugal
drainer being represented in vertical section (with driving gear) as
erected against the wall of a factory or building.
Figure 2 is an elevation of the drainer with outer casing partly
removed; Figure 3 is a half plan and half horizontal section of drainer; 1
and Figure 4 is a plan of one bleaching vat and driving gear, and also
of parts of a second and a third vat.
a, a, are pulp pipes from ordinary pulping engines; A, A, the improved
bleaching vats constructed of cast iron and furnished with ordinary
sand traps A*, and also (though not so represented in the Drawings) 2
with ordinary waste valves and steam pipes, and with water pipes; B,
agitator or paddle elevator, one in each vat, serving the double purpose
of keeping the pulp in thorough agitation, and elevating it so as to
bring it constantly into contact with the air. We find one revolution
per minute to be a proper rate of motion. The agitator consists of 2
three cast-iron plates or of boards supported by arms extending from the
shaft C, by which it is worked; D, E, F, G, worm wheel, worm shaft,
and pulley (respectively) for driving the shaft; C, H, bearings for
shaft F; K, pulp pipes (of copper) from vats to the improved or
centrifugal drainer; K*, valve and pipe for admission of water for S
washing remnant of liquor out of pulp after drained if required; L, stop-
cocks from the separate vats; N, the fixed or stationary outer casing
of the drainer, constructed of cast iron; O, the perforated plates or
wire gauze of the revolving cage of same. We consider that if plates
be used they should be of brass, or copper, or zinc, and perforated with
holes in diameter about No. 18 Birmingham wire gauge, and in number
about thirteen or fourteen to the square inch, wire gauze of brass,
copper, or zinc, may be substituted but we prefer perforated plates and

page_text: zinc as the material to be used. And we consider a speed of about 220
to 240 revolutions per minute convenient. But the size and number
of perforations and speed of driving will no doubt admit of variation.
P, cast-iron pillars supporting the perforated plates or gauze and con-
necting the top and bottom cast-iron ring plates Q and R respectively,
of the revolving part of the drainer; S, S, four brass slide valves working
on the bottom plate for (when required) discharging the drained pulp
through the brass mouth piece S* from the pulp shoot S³ or trough at
the bottom of the stationary part of the drainer into an ordinary
portable pulp box or truck S³ or any convenient receptacle for removing
it; S' is liquor shoot at bottom of the stationary part of the drainer for
receiving the liquor thrown off by the centrifugal action, and which
may be removed by a discharge pipe S³ from same shewn only in
Figure 2. T is a plate with spiral cam grooves on the under side for
working the valves S by means of studs projecting from them into the
grooves; V is a shaft, and W a hand wheel for turning the plate T, and
controlling the valves; X is a brass cone for distributing the pulp
delivered into the drainer; Y, vertical shaft communicating the
revolving motion; Z, bearing blocks, and 6 step bearing at foot of same;
c, d, bevil wheels actuating the shaft Y from driving shaft e; f, g, fast
and loose pulleys on driving shaft, and h, i, bearings in which it works
the last mentioned bearing being supported in the wall box k; lis
cast-iron framing supporting the drainer and gearing. In employing
the improved process or processes and apparatus we work the csparto
fibre or other material about one hour in the (ordinary) pulping engines
and here the bleaching liquor is added to stuff. We empty two into
one bleaching vat and mechanically agitate for four hours. The
material is then ready for going to the centrifugal drainer.
contents of each vat are in succession transferred to and treated in the
drainer, the agitation in the vats going on preparing for the drainer
at the same time that the drainer is at work. Hence the machinery
is fully employed, and in the space of twelve hours we can prepare
about 4,800 pounds weight of "half stuff," whereas to do so in the
ordinary manner would probably require six pulping engines, and six
bleaching engines, and perhaps nearly double the power we employ for
our machinery.
'
The
Also we dispense with the three or four hydraulic presses for
extracting liquor employed in the ordinary process, and very considerably

page_text: Also we save space, and as the "half stuff" requires less manipulation
there is less liability to collect dirt.
We would here remark that the drainer may and if desired is to
be used for draining off or separating any other liquors than bleaching
liquor.
Having now described the nature of the said Invention, and the
manner in which the same is to be performed, we declare that we
claim,―
The bleaching process in the manufacture of paper from esparto fibre
and other materials by the application or assistance of a mechanical
agitator or elevator in a bleaching vat or vessel as firstly herein-above
set forth.
Also, we claim, the application to draining esparto fibre and other
materials in the manufacture of paper of the centrifugal draining
process secondly herein-above set forth.
And, further we claim, the combination of these processes and the
general forms, arrangements, and combinations of parts for carrying
into effect the said separate and combined processes as herein-above
described and represented in the Drawings.
In witness whereof, we, the said John Torrance and Thomas
Torrance, have hereunto set our hands and seals, this day of
January, in the year of our Lord One thousand eight hundred
and seventy-two.
JOHN TORRANCE.
(L.S.)
THOMAS TORRANCE. (L.S.)