IMPROVE- MENTS IN THE MODE OF AND APPARATUS FOR EXTRACTING LIQUOR FROM MACERATE FIBRES EMPLOYED IN THE MANUFACTURE OF PAPER
Year: 1866

page_text: PROVISIONAL SPECIFICATION left by William Anderson at the Office
of the Commissioners of Patents, with his Petition, on the 9th January
1866.
I, WILLIAM ANDERSON, of Erith Iron Works, in the County of Kent, Civil
Engineer, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN THE MODE OF AND APPARATUS FOR EXTRACTING LIQUOR FROM MACERATE
FIBRES EMPLOYED IN THE MANUFACTURE OF PAPER," to be as follows:-
The chief object of this Invention is to extract the liquor used in boiling
straw, esparto, rags, or other similar substances used in the manufacture of
paper in the most concentrated form for the purpose of subsequent treatment
to recover the chemical substances used, or for the purpose of getting rid
of the noxious effects of the "black liquor" either by storage or removal.
According to the method at present in use the liquor in which the cut
straw or other fibrous material is boiled is greatly diluted by repeated washings
of the "stuff" or reduced fibres for the purpose of separating the chemical
solution therefrom, and a large bulk of dilute liquor is thus obtained which
renders it very costly to evaporate in order to recover the alkaline ingredients,
and which cannot be otherwise got rid of without injury to the streams into
which it may be discharged. To avoid these inconveniences and to facilitate
the recovery of the chemical ingredients at the least possible cost I empty the

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boilers (when the boiling operation is completed) of their contents, if possible
without previously adding any additional liquor, but at any rate adding the
least quantity necessary to empty the boilers; I let the stuff flow into a tank
of sufficient capacity provided with an agitator, and by means of a regulating
valve or sluice I discharge the stuff on to a travelling endless web of wire,
cloth, canvas, or felt, below which exhaust tubes may be applied if found
desirable. A portion of the liquor being thus drained away the stuff ]
under a couch roller, which presses it into the form of a thick loosely-cohering
sheet, which is then passed between a pair of pressing rollers. The sheet is
then delivered on to a second endless web, and passing under one or more
irrigating or sparging pipes over it is moistened with water or other hot or
cold liquor; thence it passes between a second pair of rolls, and so on until
by alternate washing and expressing of the liquid the desired degree of
cleanliness has been attained. The liquor pressed out by each pair of rolls
and that drained from the endless webs may be collected separately or not as
may suit the particular case, and any waste stuff that may escape is caught
by a filtering arrangement, and again passed between the pressing rollers.
My process is in this manner continuous and automatic in its arrange-
ment.
The liquor extracted as above described in a comparatively concentrated
form I submit to the action of evaporating pans, whereby I rapidly drive off
the water and economically obtain the alkaline residuum. The "stuff" when
the liquor is expressed therefrom is ready for the bleaching stage of the paper-
making process.
I would remark that the above-described apparatus for freeing macerated
fibres from the saturating solution is applicable to analogous cases in other
branches of the arts.