Improvements in the Method of and in Apparatus for Recovering and Concentrating Waste and Diluted Sulphuric Acid, and for Separating and Recovering other Acids in Mixture therewith.
Year: 1893

page_text: Date of Application, 9th Feb., 1893 ·
Complete Specification Left, 4th Nov., 1893-Accepted, 16th Dec., 1893
PROVISIONAL SPECIFICATION.
Improvements in the Method of and in Apparatus for Recovering
and Concentrating Waste and Diluted Sulphuric Acid, and for
Separating and Recovering other Acids in Mixture therewith.
Fallowfield, Manchester in the
I, IVAN LEVINSTEIN, of "Hawkesmoor"
County of Lancaster, Chemical Manufacturer, do hereby declare the nature of this
invention to be as follows:-
This invention relates to processes and apparatus for recovering and concentrating
waste and diluted sulphuric acid, and for separating and recovering other acids,
such as nitrous, nitric, hydrochloric, and acetic acids, which may be mixed therewith.
I have described in the Complete Specification left by me with my application
for Letters Patent No. 19213 dated the 26th day of October A.D. 1892 an
apparatus for concentrating sulphuric acid which I employ with certain additions
and modifications hereinafter described for the purposes of my present invention.
If it be intended only to concentrate weak sulphuric acid or mixtures of sulphuric
acid containing less than one half per cent. of nitrous compounds, I proceed in the
manner described in my former Specification by which method of procedure I' have
found that without previously, heating and concentrating in leaden and other
vessels, acid having a strength as low as 90 Tw. can be economically concentrated
to 168 to 170 Tw.
If the mixture to be treated consists of sulphuric acid inixed with nitrous com-
pounds, by way of example, and it be required to separate the nitrous compounds
and recover them as nitric acid, and at the same time to recover and concentrate
the sulphuric acid, I may proceed as follows
111
The acid mixture is conveyed into a large lead or stone cistern, or other suitable
storage tank whence it may run into the receiving tank which is arranged upon the
top of the concentrating apparatus described in my former Specification, and which
I will hereinafter call the "oven." From the receiving tank the acid flows into
and through the series of concentrating vessels, the acid vapours arising during the
process being conducted away by the trunk.
At the end of the trunk, I construct two branches, one of which leads to a
conveniently shaped lead tower or tube, and the other to an earthenware acid
resisting pipe tower, both of these towers being filled with coke or other suitable
material. Each of these towers also, is connected with a chimney or with other
means for producing a draught therein, and an arrangement is provided by means
of which water may be allowed to trickle down through the contents of the
earthenware tower.
Upon starting the fires in the oven, a damper in the branch leading to the
5 earthenware tower is opened and a similar damper in the branch leading to the
other tower is closed. The temperature of the oven is maintained at such a heat
that a thermometer in the centre concentrating vessel marks about 150 degrees C.
The sulphuric acid concentrated in the oven may be used direct for any purpose
for which it is suitable, and if not strong enough for the purpose required it may
O be pumped into a vitriol storage tank and thence pass again through the vessels in

page_text: the concentrating oven, with the difference that during this reconcentration, the
damper in the branch leading to the earthenware tower is closed and the other is
opened.
The nitrous acid, which is recovered as nitric acid, may be pumped to the top of
the earthenware tower in order to concentrate it, and be used in substitution for
water.
When large quantities of acid mixture require concentration and more than one
concentrating oven is available, I connect the trunk of one of the ovens with the
earthenware tower and that of the other oven with the lead tower, dispensing with
the branches. The first oven, connected with the earthenware tower, is used for
separating and concentrating, and the second oven for concentrating only, when
acid of high strength is required. If no reconcentration is required, the oven may
be connected by its trunk with the earthenware tower, and the lead tower may be
omitted or the arrangement may be otherwise varied. Similar methods are.
employed in treating other sulphuric acid mixtures.
In practice I have found that sulphuric acid from mixtures marking about
100 Twaddle will be concentrated to about 150 Twaddle during the first run, at a
temperature averaging about 150 degrees C., and that if this acid is then passed a
second time through the concentrating vessels in the oven, it will run out at about
from 168 to 170 Twaddle, or containing from 94 to 96 per cent. of monohydrate.
One oven with 30 glasses will concentrate 30 tons per week from 148/150 Twaddle
to 168/170, or 40 tons per week from 100 Twaddle to 150.
The hereinbefore described process for the separation and recovery of waste
products and concentrating sulphuric acid therefrom is more economical than those
at present in use, quite free from danger loss or nuisance, and is of especial value for
those who have to deal with sulphuric acid or mixtures of this acid with other acids
as bye products, without having a sulphuric acid works at hand.
When sulphuric acid works are available, the trunk leading to the earthenware
tower may, instead, be led to the works tower and the earthenware tower be
dispensed with.
am aware that mixtures of sulphuric acid and nitrous and nitric acids may be
concentrated to a low strength in leaden vessels heated externally or otherwise, but
such operations are very costly tedious and dangerous, the leaden vessels for
instance, requiring constant repairs involving loss of time and money. Moreover,
the acid thus obtained contains an objectionable amount of lead, and other
impurities, and the procsss is quite useless in dealing for example, with mixtures of
sulphuric and acetic acids.
For the production of 60 tons of concentrated acid per week as hereinbefore
described, the services of only two rectifiers are needed, one for night and one for
day duty.
Dated this 8th day of February A.D. 1893.
WILLIAM E. HEYS,
Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in the Method of and in Apparatus for Recovering
and Concentrating Waste and Diluted Sulphuric Acid, and for
Separating and Recovering other Acids in Mixture therewith.
.
1, IVAN LEVINSTEIN, of "Hawkesmoor" Fallowfield near Manchester in the
County of Lancaster, Chemical Manufacturer, 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 :-
This invention relates to processes and apparatus for recovering and con-
centrating waste and diluted sulphuric acid, and for separating and recovering

page_text: .
ther acids such as nitrous nitric hydrochloric and acetic acids which may
herewith.
I have described, in the Complete Specification left by me with my application
or Letters Patent No. 19213 dated the 26th day of October A.D. 1892, an
pparatus for concentrating sulphuric acid, which I employ with certain additions
nd modifications hereinafter described, for the purposes of my present invention.
If it be intended to do no more than to concentrate weak sulphuric acid, or
nixtures containing less than one half per cent. of nitrous compounds for example,
I proceed in the manner described in my former Specification, by which method of
procedure I have found that, without any preliminary heating and concentrating in
eaden and other vessels, acid having a strength as low as 90 Tw. can be
economically concentrated to from 168 to 170 Tw.
If the mixture to be treated consists of sulphuric acid mixed with nitrous
compounds, and it be required to separate these compounds and recover them as
nitric acid and at the same time to recover and concentrate the sulphuric acid, I
may proceed as follows:-
The acid mixture is conveyed into a large lead or stone tank or other suitable
tank or cistern, and from this it is run into the receiving tank which is arranged
at the top end of the concentrating apparatus described in my former Specification.
This apparatus I will hereinafter call the "oven." From the receiving tank the
mixture flows through the series of concentrating vessels in the oven, the acid
vapours arising during the process being conducted away by the truck through
At the end of the
which at present the vapours of condensation are led away.
trunk I construct two branches, one of which leads from the trunk to a conveniently
shaped lead tower or tube, and the other also from the trunk to an earthenware
acid resisting pipe tower, both of these towers being filled with coke or other
suitable material as is well understood. Each of these towers is also connected
with a chimney or with other means or devices for producing a draught therein,
and an arrangement is provided by means of which water may be allowed to trickle
down through the contents of the earthenware tower. Upon starting the fires in
the oven, a damper in the branch leading from the trunk to the earthenware tower
is opened, and a damper in the branch leading to the other tower is closed.
The temperature in the oven is maintained at such a point that a thermometer in
the centre concentrating vessel marks. about 150° C. The sulphuric acid con-
centrated in the oven may be used direct for any purpose for which it is suitable,
and if not strong enough for the required purpose it may be pumped into a vitriol
storage tank and thence pass again through the vessels in the concentrating oven, with
the difference that during this re-concentration the damper in that branch of the
trunk which leads to the earthenware tower is closed and the other is opened.
The nitrous acid which is recovered in the earthenware tower as nitric acid may
be used direct, or it may be pumped to the top of the tower and be used in sub-
stitution for water for further concentration and in the recovery of the acid coming
over from the oven.
When large quantities of acid mixture require concentration and more than one
5 concentrating oven is available, I may connect the trunk from one oven direct to
the earthenware tower, and the trunk from the other oven with the lead tower, and
dispense with the branches herein before described as being used in the case of a
single oven. The first oven, connected with the earthenware tower is used for
separating and concentrating the acids, the second is used for concentrating only,
50 when acid of high strength is required. If no re-concentration be required, the
second oven may also be connected with the earthenware tower and the lead tower
may be omitted, or the arrangement may be otherwise varied.
55
Similar methods are employed in the separation and recovery of the constituents
of other sulphuric acid mixtures.
In practice I have found that sulphuric acid from mixtures marking about 100 Tw.
will be concentrated to about 150 Tw. during the first run through the oven, at a
temperature averaging about 150° C. and that if this acid be then passed a second

page_text: One
time through the concentrating vessels it will run out of the oven at a strength of
from 168 to 170 Tw., or containing from 94 to 96 per cent. of monohydrate.
oven with 30 concentrating vessels will concentrate 30 tons of acid per week from
a strength of 148/150 Tw. to 168/170, or 40 tons per week from a strength of 100
to 150 Tw.
The hereinbefore described process for the separation and recovery of waste
products and concentrating sulphuric acid therefrom is more economical than those
at present in use, is quite free from danger loss or nuisance, and is of especial value
for those who have to deal with sulphuric acid or mixtures of this acid with other
acids as bye products, without having a sulphuric acid works available.
When sulphuric acid works are near and available, the trunk or the branch
trunk hereinbefore described as leading to the earthenware tower may instead be
led to the Glover tower and the earthenware tower may be dispensed with.
I am aware that mixtures of sulphuric acid and nitrous and nitric acids may be
concentrated to a low strength in leaden vessels heated externally or otherwise
but such operations are very costly and dangerous, the leaden vessels for instance,
requiring constant repairs involving loss of time and money. Moreover, the acid
thus obtained contains an objectionable amount of lead and other impurities and
the process is quite useless in dealing with mixtures of sulphuric and acetic acids for
example, I desire it to be understood therefore that I do not herein make any claim
to such processes of concentration.
For the production of 60 tons of concentrated sulphuric acid per week from
acid mixtures as herein before described, the services of only two rectifiers are
needed for the two ovens, one for night and one for day duty.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that I wish it to be
understood that I am aware of the Specification of Webb's Patent No. 2343
A.D. 1891 and 1 make no claim in this Specification to anything described and
claimed therein; but what I claim is :-
1. The methods of and process for separating and recovering acids in mixture
with sulphuric acid and simultaneously concentrating the sulphuric acid, substantially
as and by the means herein before described.
2. In apparatus for separating and recovering the constituents of mixtures of
sulphuric acid with other acids, the combination and arrangement with a sulphuric
concentrating oven of the type set forth, of an earthenware or a Glover tower, a
.lead tower, and damper controlled branches leading from the concentrating oven
trunk to the towers, substantially as hereinbefore described.
3. In apparatus for separating and recovering the constituents of mixtures of
-sulphuric acid with other acids, the combination and arrangement with two sulphuric
acid concentrating ovens of the type set forth, of an earthenware or Glover tower
connected by a trunk with one of the ovens, and a lead tower connected by a trunk
with the other oven, substantially as herein before described.
Dated this 3rd day of November A.D. 1893.
WILLIAM E. HEYS,
Agent for the Applicant.