IMPROVEMENTS IN THE MANUFACTURE OF SODA AND CARBONATE OF SODA
Year: 1865

page_text: LETTERS PATENT to Joseph Pierre Gillard, of Paris, France, Civil
Engineer, for the Invention of "IMPROVEMENTS IN THE MANUFACTURE OF
SODA AND CARBONATE OF SODA."
Sealed the 16th January 1866, and dated the 22nd July 1865.
PROVISIONAL SPECIFICATION left by the said Joseph Pierre Gillard at
the Office of the Commissioners of Patents, with his Petition, on the
22nd July 1865.
I, JOSEPH PIERRE GILLARD, of Paris, France, Civil Engineer, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN THE MANUFAC
TURE OF SODA AND CARBONATE OF SODA," to be as follows: --
This Invention has for its object improvements in the manufacture of soda
and carbonate of soda. In the Provisional Specification on which I obtained
Provisional Protection, dated the 16th July 1861, there is described a process
for producing soda by placing common salt in a retort and heating it to a
high temperature, at the same time projecting superheated steam on the salt;
this process, however, requires considerable modification and addition to render
it practically useful, and my present Invention applies to such modifications
and additions.
I now in place of conducting the process in a retort employ a reverberatory
furnace for the purpose, and I employ so high a heat as to melt the salt and
render it quite liquid; and in place of employing superheated steam at any
ordinary temperature, I heat it to 1800° Fahrenheit, or higher, so that it is
brought in contact with the salt when it is in the nascent state of decom-
position, and I either project this extremely highly heated steam on to the
melted salt, or I cause the steam to pass into and amongst it by means of a
[Price 8d.]

page_text: pipe or pipes, so that it may bubble up through the salt, the pipe or pipes
being made of platinum and provided with dispersing roses or with small
holes for the steam to pass through The steam also is heated by passing it
through pipes of the same material kept at a white heat, and containing
several diaphragms of gauze of the same metal, whilst platinum sponge or
platinum block may be placed between the said diaphragms in the pipe or
pipes. By proceeding as above described the common salt becomes rapidly
converted into caustic soda, and then, if desired, this may be made into
carbonate by blowing a stream of carbonic acid gas into it by means of a
suitable pipe or pipes The hearth or working bed of the furnace may be
made moveable, so that at the end of the operation it may be lowered away
from the perforated pipe or pipes and the charge removed, or the bed may
be stationary and the pipe or pipes be moveable A layer or stratum of well-
beaten soda is constantly to remain on the bed, in order to prevent the soda
from acting injuriously on the bricks and forming a sihcate or aluminate of
soda.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Joseph Pierie Gillard in the Great Seal Patent Office on the
22nd January 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOSEPH
PIERRE GILLARD, of Paris. France, Civil Engineer, send greeting
WHEREAS Her most Excellent Majesty Queen Victoria, by ller Letters
Patent, bearing date the Twenty-second day of July, in the year of out Lord One
thousand eight hundred and sixty-five, in the twenty-ninth year of Her reign.
did. for Ilerself, Iler heirs and successors, give and grant unto me, the said
Joseph Pierre Gillard. Her special licence that I. the said Joseph Pieric
Gillard, my executors, administrators, and assigns. or such others as I. the said
Joseph Pierre Gillard. my executors, administrators. and assigns. should at
any time agree with, and no others, from time to time and at all times there-
after during the term therein expressed, should and lawfully might make, use,
exercise, and vend, within the United Kingdom of Great Britain and Ireland,
the Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
THE MANUFACTURE OF SODA AND CARBONATE OF SODA," upon the condition (amongst
others) that I, the said Joseph Pierre Gillard, my executors or administrators,
by an instrument in writing under my, 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

page_text: 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 I, the said Joseph Pierre Gillard, do hereby declare
the nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement:-
The Invention has for its object improvements in the manufacture of soda
and carbonate or bicarbonate of soda, and refers more especially to certain
improvements in a mode of manufacturing the said articles for which a Pro-
visional Protection was granted to me on the 16th of July 1861, in the Pro-
visional Specification of which I described a process for producing soda by
placing common salt in a retort and treating it to a high temperature, at the
same time projecting superheated steam on the salt; this process, however,
requires considerable modification and addition to render it practically useful
and my present Invention applies to such modifications and additions.
I now in place of conducting the process merely in a retort I employ
either a reverbaratory furnace for the purpose, or a very large vessel of suit-
able shape placed in a suitable furnace, allowing of being heated to the
required degree, and I employ so high a heat as to melt the salt and render
it quite liquid; and in place of employing superheated steam at any ordinary
temperature, I heat the steam to 1800° Fahrenheit, and transform the same
into what is called dissociated steam, so that it is brought in contact with the
liquid salt when it is in the nascent state of decomposition, which state of
decomposition or dissociation I obtain by causing the steam to pass first
through tubulated blocks or large pieces of cast or wrought iron, steel, or
other suitable metal or material, kept at white heat, and afterwards through
highly heated pipes of platinum. in the interior of which are situated a suitable
number of diaphragms of fine platinum wire gauze, or bundles of platinum
wire, or finely perforated plates of platinum, so as to cause the superheated
steam to pass through a large quantity of minute holes for the purpose of, by
thus coming in contact with a large surface of highly heated platinum, the
steam should become dissociated or decomposed in its constituent parts
(oxygen and bydrogen) in the nascent state, in which state I conduct the
same by means of a pipe or pipes of platinum into and among the liquid
salt so that it may bubble up through the said salt, the pipe or pipes being
provided with dispersing roses or with small holes for the dissociated steam to
pass through; or the said dissociated steam may be made to impinge on the
surface of the liquid salt, or of a thin layer of this latter falling gradually from
the retort or other vessel in which the salt is melted into one or more highly

page_text: neated vessels, in which, by the effect of the dissociated steam on the molten
salt the decomposition and transformation of this latter into caustic soda 15
effectuated, the hydrochloric acid gas evolved during the process being allowed
either to escape in the air or to be condensed in water by any of the known
methods The caustic soda whilst in the liquid state is allowed to run off in
suitable receiving vessels, or the same may be converted into carbonate or
bicarbonate of soda by blowing a stream of carbonic acid gas into it.
Having thus described the nature of the process, I now will describe more
particularly the arrangement of the furnace and other means I prefer to make
use of for performing the same
In the annexed Drawings Fig 1 shows a transverse vertical sectional view
of the furnace or apparatus The same consists of a large arch A of brick-
work lined with fire-bricks and provided with a fire-place B, fire-bars C, and
ash-pit D, the length of the furnace ought not to be less than 15 feet, and of
a width in the inside of from 6 to 7 feet. Above the fire-place B is provided
a small arch E of fire-bricks, along the inside of which arch are situated at
each side the pipes F of platinum, which rest on suitable projecting parts of
the brickwork, and which pipes are in communication with two large blocks
G&G'. or pieces of cast or wrought iron, steel, or other suitable material. one
of which blocks is situated at each side of the arch E on proper props of
brickwork; the blocks G & G are of a square shape, and each of them is
perforated through its full length with several (by preference four) tubular
perforations g, forming so many pipes. each two of which are in communication
with each other, and in which tubular perforations or pipes the steam obtained
from a suitable boiler or steam generator is conducted by pipes II in such
manner that this steam is made to circulate first through the perforations g of
the blocks, and afterwards through the platinum pipes F, provided in the
interior with a large number of diaphragms of platinum wire gauze, or with
platinum plates provided with a large quantity of munute perforations, or with
bundles of fine platinum wire, so as to cause the steam to come in contact
with a large number of highly heated platinum surfaces, and thereby become
decomposed into its constituent parts, or brought into the nascent or dis-
sociated state Above the arch E is situated a D-shaped retort I, of cast iron,
steel, or other suitable metal. provided with a moveable lid i and pressing
screw for allowing of hermetically sealing the retort. Fig. 2 shows a longi-
tudinal sectional view of the retort I and of the vessel M, in which the dis-
sociated steam is caused to act on the molten salt The chloride of sodium
or common salt I make use of for the manufacture of soda is thrown into the
retort by means of a pipe K and funnel K passing through the top and

page_text: arch A of the furnace; after each charge the pipe K is to be hermetically
closed by a plug. In this retort I the salt is melted, and in that state allowed
to run off gradually at the further end of the retort by means of one or two
pipes L&L' into one or two longitudinal vessels or cylinders M, situated in
the further end of the furnace, which cylinders are closed at each end by
suitable lids, through the anterior one of which the dissociated steam is pro-
jected through and amongst the molten salt whilst falling in a thin stream, or
by small portions at a time, from the retort I into the cylinders M, in which
latter the dissociated steam continues to impinge on the surface of the molten
salt, by the effect of which the salt will become decomposed and transformed
into caustic soda, which latter remaining in the liquid state runs off by means
of a dipping pipe N, situated towards the further end of the cylinder or
cylinders M, into a receiving vessel O, the hydrochloric acid evolved during
the process being allowed to take its exit by the pipe P; the vessel O is
further provided with an overflow pipe Q, by means of which the liquid soda
is allowed to run off into iron vessels provided with the necessary means for
preventing the air from coming in contact with the soda in the vessel. By the
apparatus just described the dissociated steam is made to act in a continuous
manner on a thin layer or stream or small portions of the molten salt at a
time.
A modification of this arrangement, for the purpose of allowing to act at
once on large quantities of molten salt, consists in replacing the cylinder or
cylinders M by a suitably large receiving vessel or pot R, as shown for this
latter part in vertical sectional view in Fig. 3, in which vessel or pot, situated
in the furnace towards the further end of this latter. In the vessel R are
inserted the cast or wrought iron pipes W, the free end of which is perforated
with a number of small holes, or provided with a dispersing rose n, whilst the
other end of them serves as a boss for receiving the ends of the platinum
pipes F; the pipes W are situated either in the manner as shown in w & w',
or as shown in to. S is the tube by which the molten salt falls into the
vessel R; T is the pipe for the exit of the hydrochloric acid gas; and U, an
overflow pipe by which the caustic soda leaves the vessel R, which soda being
of less specific gravity than the salt will raise on the top of the latter. By
this apparatus the decomposition of the salt may also take place in a con-
tinuous manner. Or if it should be desirable that the action of the dissociated
steam on the salt should be continued for a longer period the overflow pipe U
is to be shut, and the soda allowed to run off, when the decomposition of the
contents of the pot R is completed by means of a pipo V, situated either a
little above or opening in the bottom of the pot, after which a fresh charge of

page_text: molten salt is allowed to run into this latter to be acted upon by the dis-
sociated steam. The caustic soda obtained by either of these apparatuses may,
if required, be transformed into carbonate or bicarbonate of soda by blowing
a stream of carbonic acid gas into the liquid caustic soda.
Having thus described and particularly ascertained the nature of my Inven-
tion, and the manner in which the same is or may be carried into effect, I
would declare in conclusion that I do not intend to confine or restrict myself
to the precise details of the arrangements above described, as many variations
may be made therefrom without deviating from the principles or main features
of the Invention; but what I consider to be novel and original, and therefor
claim as the Invention secured to me by the herein-before in part recited
Letters Patent is,-
1ly, manufacturing caustic soda by acting on molten chloride of sodium
(common salt) with dissociated steam. viz., superheated steam brought into
the nascent or decomposed state.
2ly, obtaining dissociated steam for the purpose just described, by causing
steam to pass through the tubular perforations of highly heated blocks or
pieces of cast or wrought iron, steel, or other suitable metal or material, and
from thence through highly heated pipes of platinum provided in the inside
with a large number of diaphragms or partitions of platinum wire gauze. per-
forated plates of platinum, or bundles of platinum wire
3ly, the process and apparatus described in respect to Figs 1 & 2 for
causing the dissociated steam to act on a comparatively thin stream or
on small quantities of molten salt at a time. and. If required. in a continuous
manner.
4ly. the process and apparatus described in reference to Fig 3 for acling
either in a continuous manner or at suitable intervals on a large quantity of
molten salt at a time.
5ly, the general arrangement and combination of parts of the apparatus
above described and illustrated in the annexed Drawings
In witness whereof. I. the said Joseph Pierre Gillard. have hereunto set
my hand and seal, this Sixteenth day of January, in the year of our
Lord One thousand eight hundred and sixty-six.
J. P. GILLARD. (LS)