Improvements connected with the Application and Utilization of the Residual Liquors Produced in the Manufacture of Vegetable Parchment Paper.
Year: 1895

page_text: Date of Application, 10:h Oct., 1895
Complete Specification Left, 10th July, 1896-Accepted, 25th July, 1896
PROVISIONAL SPECIFICATION.
Improvements connected with the Application and Utilization of
the Residual Liquors Produced in the Manufacture of Vegetable
Parchment Paper.
I, JOHN SAMUEL RIGBY, of 35 Bagot Street, Wavertree, Liverpool, in the County
of Lancaster, Chemical Engineer, do hereby declare the nature of this invention
to be as follows:-
In the manufacture of vegetable parchment paper, there is discharged from the
apparatus more or less dilute or diluted sulphuric acid, which is produced or brought
about generally, parily by the passage through water of the paper in the initial stages
of its manufacture, charged with or containing the stronger sulphuric acid used in
its treatment and partly by the water which is used-frequently in the form of
jets to wash the acid from the paper after it has been so treated. This "waste"
sulphuric acid I take and render serviceable by using it in conjunction with other
sulistances, and in the manner and by means hereinafter described, to produce certain
useful products.
It is preferred, in the performance of this invention. to treat the paper in its
parchmentizing operation when charged with sulphuric acid, to the action of a water
bath, i.e. by passing it through a vessel containing, at the start, water, and then in a
separate apparatus or part of the apparatus, to a washing action, as by jets of water,
and in such a case it is advantageous to press as much liquor from the paper as
conveniently possible as it comes from the first bath, and carry such liquid back to
the bath or to the liquor taken therefrom; this being suitably done by passing it
between rollers, and these rollers should also be driven to assist the passage of the
paper through the machine, so as not to form a hindrance to its passage or put a
dangerous strain upon it.
The liquors from these two parts of the apparatus will be of different strengths or
states of dilution, and they are taken, in one mode of carrying out this invention,
separately, and employed in conjunction with different substances for making different
products.
The stronger liquor or acid will be that from the first bath, and this I utilize
in conjunction with carbonate of magnesia, generally called magnesite, to produce
sulphate of magnesia. This production 1 carry out by employing a tower of
considerable height within which the magnesite is contained, and causing the acid
to fall and flow down over it, it being pumped up to the distributing part at the
top of the lower. The acid is thus passed over the magnesite until it is converted to
sulphate of magnesia. The carbonic acid given off being of good quality, can be
usefully employed in manufactures.
The more dilute acid from the second washing treatment of the paper I take and
use in conjunction with calcium chloride in suitable proportions to produce the
hydrated calcium sulphate. In the operations connected with this production, the
acid and calcium chloride are thoroughly mixed by suitable means; the product is
then washed and so ridded of free acid; and then is ridded of moisture, or excess
of moisture, by forcing it through a filter press, which extracts or forces out such
excess of moisture, and in this condition is ready for packing.
Dated this 9th day of October 1895
CHEESBROUGH & ROYSTON,
15 Water Street, Liverpool, Applicant's Patent Agents.

page_text: GUMI LETI SIECIFICATION.
Improvements connected with the Application and Utilization of
the Residual Liquors Produced in the Manufacture of Vegetable
Parchment Paper.
I, Jons SAMUEL RIGBY, of 85 Bagot Street, Wavertree, Liverpool, in the County
of Lancaster, Chemical Engineer, do hereby declare the nature of this invention
and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement :—
In the manufacture of vegetable parchment paper, there is discharged from the
apparatus more or less dilute or diluted sulphuric acid, which is produced or brought
about generally, partly by the passage through water of the paper in the initial
stages of its manufacture, charged with or containing the stronger sulphuric acid used
in its treatment and partly by the water which is used-frequently in the form
of jets to wash the acid from the paper after it has been so treated. This "waste
sulphuric acid I take and render serviceable by using it in conjunction with other
substances, and in the manner and by means hereinafter described, to produce certain
useful products.
"
It is preferred, in the performance of this invention, to treat the paper in its
parchmentizing operation when charged with sulphuric acid, to the action of a water
bath, Le, by passing it through a vessel containing at the start water, and then in
a separate apparatus or part of the apparatus, to a washing action, as by jets of
water, and in such a case it is advantageous to press as much liquor from the paper
as conveniently possible as it comes from the first bath, and carry such liquid back
to the bath or to the liquor taken therefrom; this being suitably done by passing it
between rollers, and these rollers should also be driven to assist the passage of the
paper through the machine, so as not to form a hindrance to its passage or put a
dangerous strain upon it.
The liquors from these two parts of the apparatus will be of different strengths
or states of dilution, and they are taken, in one mode of carrying out this invention,
separately, and employed in conjunction with different substances for making different
products.
The stronger liquor or acid will be that from the first bath, and this I utilizo
in conjunction with carbonate of magnesia, generally called magnesite, to produce
sulphate of magnesia. This production I carry out by employing, preferably, a
tower of considerable height within which the magnesite is contained, and causing the
acid to fall and flow down over it, it being pumped up to the distributing part at
the top of the tower. The acid is thus passed over the magnesite until it is converted
to sulphate of magnesia. The carbonic acid given off being of good quality, can be
usefully employed in manufactures.
The more dilute acid from the second washing treatment of the paper I take,
and use in conjunction with calcium chloride in suitable proportions, to produce
the hydrated calcium sulphate. In the operations connected with this production,
the neid and calcium chloride are thoroughly mixed by suitable means; the product
is then washed and so ridded of free acid; and then is ridded of moisture, or excess
of moisture, by forcing it through a filter press, which extracts or forces out such
excess of moisture, and in this condition is ready for packing,
A drawing illustrating this invention is hereto annexed, which shews in plan the
general arrangement and combination of apparatus for effecting the purposes of
this invention.
Referring to the drawings, A represents three sets of paris of apparatus for
manufacturing vegetable parchment from paper such as ordinarily used in such
manufacture.

page_text: In this apparatus, a represents the tank in which the original acid, that is sulphuric
acid, is contained, and through which the paper to be parchmentized is first passed.
a' is the tank containing water through which the paper thus treated with sulphuric
acid is first passed, and which, when the process has been conducted for a short
period of time, becomes strongly acidulated; this liquor is heroafter called the
strong acid.", a is the tank in or over which the paper so treated is passed and
washed, and wherein the water becomes slightly acidulated comparatively; this
liquor is hereafter called the "weak acid." is a pipe common to the tanks a¹ by
which the strong acid is conducted away from them, such pipe communicating with
these tanks a' by separate pipes ; while d is a main pipe by which the weak acid
is carried off from the tanks, it being connected with such tanks by the pipes e.
f is a tank into which the strong acid from pipe is delivered; and another tank
into which the weak acid from the pipe dis delivered. These two tanks form the
storage and supply tanks for the sirong and weak acids, respectively, and from
them these liquors are drawn off for use in their separate processes and apparatus
for the manufacture of the substances specified.
are dissolving cisterns or towers in which carbonate of magnesin (magnesito)
is introduced; and the strong acid from passes to it by the pipes and branches.
In these cisterns or towers the magnesite is dissolved. is a tank in which the
liquor from the cisterns or towers which flows into it by the pipe seitles, and
impurities such as oxide of iron, removed; the flow from the one to the other taking
place by the pipe j. are tanks connected by pipes with the tank &, wherein the
crystallization of sulphate of magnesia takes place.
-The
The operation of this part of the processes and apparatus is as follows:-
sulphuric acid from the tank being added to and mixed with the magnesite in the
cisterns or towers 4, sulphate of magnesia is formed, with the evolution of carbonic
acid; and if desired this dissolving of the magnesite, and action, may be expedited
by applying heat to the substances in the tanks h. The carbonic acid given off may
be collected from the tanks and used for any purpose for which it may be suitable,
either in its gaseous form, or condensed liquid form. The liquor or solution from
the tanks circulates into and through tank and back to the tanks through the
pipes and, and in the tank k, which acts as a settling tank, impurities as stated,
such as oxide of iron, are deposited and removed. The liquor at the desired strength
and state is then delivered or discharged from the tank & to the tanks 1, wherein
the sulphate of magnesia crystallizes; and the crystals are removed from them in
the usual or any known suitable way.
As a modification of the above, in some cases, the solution from before it is
delivered to the crystallizing tank may be first concentrated by evaporation, to some
extent.
By this portion of the process and apparatus, the strong acid from parelmentizing
apparatus is rendered serviceable and utilized in the production of sulphate of
magnesia and carbonic acid.
With regard now to the part of the apparatus in which the weak acid is used, this
comprises mechanical mixing apparatus m connected with the weak acid tank g by
the pipes g; a tank 7 containing calcium chloride and connected with the mixers m
(of any known suitable mechanical kind) by a pipe ; washing tanks or vessels n,
connected with the mixers m by pipes ; and filter presses o.
In the process
connected with this part of the plant, the weak acid is taken from the tank by the
pipes g, and delivered into the mixing apparatus m; and here calcium chloride from
the tank g is added to it in sufficient quantity as will be well known to produce
hydrated calcium sulphate. From the mixers m, the solution or liquor is conveyed
to the washing vessels n by pipes n', in which it is agitated, and washed with water,
and free acid (hydrochloric acid) is got rid of. From the washing apparatus n, the
solution or liquor is passed to the filter presses o, and the water, that is the excess
of free water, is removed; and in this condition the hydrated calcium sulphate
(silkite) is ready for packing.
If desired the liquor or solution is conveyed direct from the mixing vessels m to

page_text: the filter presses o, without passing through the washers a, and washed in the
presses o.
It will be understood, that in the apparatus shown the different tanks, vessels, or
parts may bo of any known suitable kinds, and that the pipes, conduits, or parts
will be provided with suitable valves, taps, or other fittings, for controlling the flow
of liquids, and otherwise carrying on the process.
Having now particularly described and ascertained the nature of this inven
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The application and utilization of the wasto sulphuric acid liquors discharged
from the vegetable parchmentizing tanks or apparatus of vegetable parchment
manufacturing machinery, and the manufacture of substances described, in the
manner and by the means substantially as herein set forth.
2. In the manufacture of sulphate of magnesia and hydrated calcium sulphate, the
particular combination of apparatus and process by which the waste acid liquors from
vegetable parchment making manufacturing machinery are separated into strong and
weak, and treated, and such neids subsequently mixed with carbonate of magnesia,
and chloride of calcium, respectively, and subsequently treated and operated upon :
as set forth and shewn.
Dated this 9th day of July 1896.
CHEESBROUGH & ROYSTON,
15 Water Street, Liverpool, Applicant's Patent Agents.