IMPROVEMENTS IN THE MANUFACTURE OF CHLORINE
Year: 1868

page_text: LETTERS PATENT to Henry Deacon, of Appleton House, Appleton, in
the County of Lancaster, Alkali Manufacturer, for the Invention
of "IMPROVEMENTS IN THE MANUFACTURE OF CHLORINE,"
Sealed the 9th October 1868, and dated the 29th April 1868.
PROVISIONAL SPECIFICATION left by the said Henry Deacon at the
Office of the Cominissioners: of Patents, with his Petition, on the
29th April, 1868.
I, HENRY DEACON, of Appleton House, Appleton, in the County of
Lancaster, Alkali Manufacturer, do hereby declare the nature of my said
Invention for "IMPROVEMENTS IN THE MANUFACTURE OF CHLORINE," to be as
follows:-
Chlorine is usually produced on the large scale by heating peroxide
of manganese in aqueous solution of hydrochloric acid, the materials if
perfectly utilised yielding one equivalent of free chlorine and one
equivalent of chloride of manganese in solution (as a bye product of
little value) for every one equivalent of peroxide of manganese and
two equivalents of hydrochlorine acid employed,

page_text: My improvements consist in heating in a current of hydrochloric acid
gas and atmospheric air of oxide of copper and oxide of manganese, or
of other similar metallic oxides or compounds having similar com-
position. In this manner the whole of the hydrochloric acid gas may
be decomposed at a moderate temperature, say about 400 F.; the
chlorine of the acid gas is set free, and the hydrogen of the acid gas
combines with atmospheric oxygen or water. The mixture of oxides
remain unaltered, and the process becomes continuous. The chlorine
thus obtained is mixed with the vapour of water, any hydrochloric acid
escaping decomposition or afterwards formed; the nitrogen of the atmo-
spheric air and any of its oxygen left are combined. The water and
hydrochloric acid may be separated by condensing, and the chlorine
absorbed from the remaining gases and utilised in any well-known
manner.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Henry Deacon in the Great Seal Patent Office
on the 29th October 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
DEACON, of Appleton House, Appleton, in the County of Lancaster,
Alkali Manufacturer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-ninth day of April, in the year
of our Lord One thousand eight hundred and sixty-eight, in the thirty-
first year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Henry Deacon, Her special license
that I, the said Henry Deacon, my executors, administrators, and
assigns, or such others as I, the said Henry Deacon, my executors,
administrators, or assigns, should at any time agree with, and no
others, 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
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
THE MANUFACTURE OF CHLORINE," upon the condition (amongst others) that
I, the said Henry Deacon, my executors or administrators, by an instru-

page_text: ment in writing under my hand and seal, 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 I, the said Henry Deacon, do hereby declare
the nature of my said Invention, and in what manner the same is. to
be performed, to be particularly described and ascertained in and by the'
following statement, that is to say :-
...
'
.
"
My improvements consist in the continuous production of chlorine by.
passing a current of hydrochloric acid gas and atmospheric air over a
mixture of oxide of copper and oxide of manganese, or of such other
metallic compounds as are hereafter referred to and which I find will
produce similar effects. The materials employed should be heated to
such a temperature that the hydrochloric acid gas may be decomposed
and its chlorine liberated. The decomposing power of the metallic
compounds remains permanently active, and the process is therefore a
continuous one. The chlorine thus produced will be found to be mixed
with the vapour of water and with any hydrochloric acid which has
escaped decomposition or been afterwards formed, and also with the
nitrogen of the atmospheric air employed, and also with any of the
oxygen that may have been left uncombined. The water and hydro-
chloric acid may be separated by condensation, and the chlorine may
be absorbed from the remaining gases and. utilized in any well-known
manner.
:
.
In this process oxygen is the element required to unite with the.
hydrogen of the hydrochloric acid, and to set free the chlorine any.
available supply of oxygen may therefore be employed, but atmospheric.
air is I consider the cheapest source.
1
In carrying out this process one at least of the compounds employed
must be of such a character that it will have the power of uniting with
oxygen, either at the ordinary temperature or when heated, and when
it is afterwards treated with hydrochloric acid and heated either alone*
or in the presence of oxygen it must possess the property of decomposing'
such acid and of ultimately yielding chlorine as one of the results of
the decomposition. By applying this test to the metallic compound'

page_text: employed the suitability of the mixture will be practically ascertained
without difficulty.
My process is essentially a continuous one, and it depends upon the
power of one or more of the compounds employed to cause the various
reactions just described. The hydrochloric acid gas and air, which is
by preference previously heated, are passed over the heated metallic
compounds, which absorb more or less of the hydrochloric acid gas and
become saturated therewith, the saturation depending in part upon the
temperature employed, and then so long as the temperature remains
constant no further change is noticeable in the compounds, but the
hydrochloric acid gas and the oxygen of the air react on each other
in the presence of these compounds, and a continuous stream of hydro-
chloric acid and air entering the apparatus employed results in the
issue of a continuous stream of chlorine and of the vapour of water
mixed of course with nitrogen from the air, unused oxygen, and
hydrochloric acid.
There are several compounds which can be employed in carrying out
my Invention, of which salts of manganese, lead, and copper are usually
the most available either alone or in combination, as may be readily
ascertained by applying the test above referred to. Of these compounds
I prefer the compounds of copper because of the high temperature
necessary when using the compounds of manganese and lead, except
when the compounds of manganese are employed as a diluent in order
to prevent the fusing and caking of other more fusible compounds.
Of the compounds of copper I prefer the sulphate of copper, which
may be employed in the following manner:-Into a strong solution
of sulphate of copper I dip or immerse or impregnate common clay
or fire-clay bricks or pipes, which after saturation I place in retorts
or flues heated externally, and through which is made to pass by means
of pressure or draught the heated mixture of hydrochloric acid gas
(usually obtained from the manufacture of sulphates of soda or potash
from their chlorides) and atmospheric air, by which means and arrange-
ment large surfaces of the compounds of copper are exposed to the
action of the heated gases. To obtain a successful result attention must
be paid to the temperature of the gases which will vary according to
the materials employed, say from about 400° F. to 800° F. or 850° F.;
if the temperature be raised to too high a point it will be found that

page_text: certain compounds of copper are volatilized, whilst on the other hand
if the temperature is allowed to fall too low the decomposition becomes
less active, and ultimately the hydrochloric acid gas is absorbed until the
compounds become saturated therewith and decomposition ceases.
The
apparatus is also slow in recovering its activity at the working tempera-
ture unless it be temporarily raised above it. One advantage arising from
the employment of compounds of copper is the comparatively low
temperature at which they act, but for practical purposes they require
to be mixed with some other body or compounds to prevent their fusing
together; burnt clay will be found to be efficient for this purpose. With
compounds of lead a full red heat must be employed, and then by
preference only the chlorides and other soluble salts of lead or com-
pounds soluble. in hydrochloric acid are to be mixed with burnt clay
or other similar porous substances, as those only are suitable for the
desired purpose. Indeed it may be stated that compounds of lead are
not so advantageously employed as are the compounds of copper, owing
to the increased temperature required, and the consequent difficulties
thereby involved arising in part from the volatility of the lead com-
pounds.. With the compounds of manganese a still higher temperature
than that required for compounds of lead is necessary, and excepting
the non-volatility of compounds of manganese the objections are
greater against its employment than against the compounds of lead.
I annex a Sheet of Drawings illustrating one form of furnace which
may be employed in carrying out my said Invention. This furnace
may either be composed entirely of brickwork, or it may consist of a
cast-iron casing or chamber filled with and set in brickwork; the
latter, which is the one illustrated, is more costly in erection and
repairs, but prevents more effectually any escape of the gases or their
dilution with the products of combustion from the smoke flues.
Figure 1 represents a side elevation of the chlorine furnace; Figure 2
is a longitudinal vertical section of the same taken along the line i, k,
in Figure 5; Figure 3 is a transverse vertical section taken along
the line l, m, in Figure 2; Figure 4 is a horizontal section taken
through the upper smoke flue along the line a, b, (Figure 2); Figure 5
is a horizontal section through the gas decomposing flue along the
line c, d, (Figure 2); Figure 6 is a horizontal section through the
gas heating fiue taken along the line e, f, (Figure 2); and Figure 7

page_text: is a horizontal section through the bottom smoke flue taken along the
line g, h, Figure (2). In these Figures, 1 is the fire-place or furnace
proper; and 2, 2, are the smoke flues which are arranged in zig-zag
fashion beneath and above the gas heating and decomposing flues;
3 is the gas heating flue constructed in a zig-zag form, the gas entering
by an inlet pipe, and after traversing the entire length of flue passes
into the zig-zag decomposing flues 4, 4; these flues are filled with drain
pipes (partly shown in Figures 2, 3, and 5) soaked in' solution of sulphate
of copper or other decomposing material as described herein; 7 is the gas
outlet pipe leading from the decomposing flue to a'condenser; 5 is a
cast-iron chamber or casing built inside the brickwork and enclosing
the gas heating and decomposing flues 3 and 4, whereby an escape or
loss of gas through leakage is entirely prevented; the casing 5 may be
dispensed with however if desired.
..
Figure 8 of the Drawings represents the combination of a chlorine
furnace such as described above with a close salt cake " or sulphate
of soda furnace condenser and bleaching powder chamber: In this
Figure, 6 represents the closed "galt cake" pot or furnace; 7, the
salt cake oven or roaster; 8, the chlorine furnace of the same or
similar construction to that herein-before described and illustrated, the
supply of hydrochloric acid gas being obtained from the salt cake
furnace or pot 6 by a pipe 91 for that purpose, as shown; 9, 9, are
the cooling pipes leading to the bottom of the condensing tower 10.
From the top of this tower a pipe leads into a bleaching powder
chamber 11, which communicates by a short pipe with the chimney 12.
A furnace of the size given will produce sufficient chlorine to make
about 3 tons of bleaching powder per twenty-four hours with the
experience which is at present possessed, but I believe with further
experience this quantity will be materially increased. This arrangement
gives a current of chlorine varying in quantity according to the evolution
of hydrochloric acid gas from the "salt cake" furnace which varies
at each charge, being strong at the commencement and feeble at the
end. Where a uniform current of chlorine is required several "salt
cake" furnaces may be arranged to one chlorine furnace and charged
iu rotation, one furnace charge working off as another is beginning,
and so on; or where a smaller but regular current of chlorine is required
I prefer to use an aqueous solution of hydrochloric acid (as strong

page_text: as convenient) as the source of hydrochloric acid gas. I evaporate this
aqueous solution in any convenient manner, running into the evapora-
ting apparatus a constant stream of the aqueous acid to maintain a
constant stream of acid vapour. This is mixed with the necessary
quantity of air and then passed through the chlorine furnace. When
using aqueous hydrochloric acid more vapour of water in proportion
to the chlorine passes through the apparatus, which necessitates pro-
vision in the size and proportion of the various parts of the apparatus,
which will be evident to practical men. The aqueous hydrochloric
acid as obtained from the ordinary "salt cake " process is fit for use
in this way, and by its use the two processes of "salt cake" and
chlorine making can be separately and simultaneously conducted.
It will be noticed that I prefer to heat the hydrochloric acid gas and
the atmospheric air before passing them into the decomposing portion
of the apparatus. The arrangement given has the advantages of
compactness and keeps the intense heat of the fire from the com-
pounds of copper, but the apparatus may be varied to a great extent
and in particular the primary heating of the gases may be effected
in one apparatus and the decomposition in another, and it must be
borne in mind that the decomposition itself is attended with evolution
of heat, and therefore with a properly regulated supply of heated
hydrochloric acid gas and air and suitably protected decomposing
apparatus the latter will require but little or no external application
of heat, but the working temperature can be maintained by due atten-
tion to the temperature of the current or gases passing into the de-
composing apparatus. Various methods by which the waste heat of
the salt cake furnaces may be employed for heating these gases
will suggest themselves to practical men. Hydrochloric acid gas passed
through the apparatus must be mixed with so much air as will give
rather more than one equivalent of oxygen for every two equivalents
of hydrogen contained in the hydrochloric acid gas. It is not necessary
to dry the air previously, but its carbonic acid can be previously removed
if desired by use of lime or of alkaline solutions as is well understood.
The gases issuing from the furnaces will consist of chlorine, of the
nitrogen of the air of any surplus or uncombined oxygen, the vapour
of water undecomposed, hydrochloric acid gas, and any other gases
either present in the air or originally mixed with the hydrochloric
acid gas, or which may have leaked into the apparatus; in other words,

page_text: the chlorine will be largely diluted and probably mixed with more
or less carbonic acid and other gases. The hydrochloric acid. gas
and vapour of water may be removed from the mixture by con-
densation and cooling alone, and the subsequent use of a scrubber or
of a column of dry coke to remove water mechanically carried with
the current is usually sufficient, otherwise the condensation can be
completed by the use of a dilute solution of hydrochloric acid, which
absorbs mere traces of chlorine, but usually enough hydrochloric acid
exists in the gases to condense in the water and expel the chlorine
therefrom and then water alone is necessary. The chlorine present
is left available for all purposes not interfered with by its dilution with
the gases before named, as, for example, for the manufacture of bleaching
powder, especially when not required of the highest strengths, and also
for the manufacture of other products, such as chlorate of potash.
1
Having now described my Invention I wish it to be understood that
I do not claim the use of chloride of copper for the production of
chlorine from hydrochloric acid by successive operations, such as evolving
part of the chlorine from the chloride of copper by heat and then oxidising
the subchloride thus produced, and subsequently adding hydrochloric acid
to this subchloride in order to reproduce the chloride of copper ready for
the recurrence of the operations which is an intermittent process; nor do
I claim the use of chloride of manganese along with liquid or aqueous
hydrochloric acid and heated air for the production of chlorine; but
what I claim and desire to be secured to me by the before in part
recited Letters Patent is,-
First. The continuous production of chlorine by passing a current
of hydrochloric acid gas and atmospheric air, by preference in a heated
condition, over heated compounds, such as those herein-before referred
to, which or one of the elements of which must have the power of
absorbing oxygen either before being heated or when heated, and must
possess when subsequently treated with hydrochloric acid and heated
eithor alone or in the presence of oxygen the power of decomposing
such acid and of ultimately yielding chlorine as one of the results of
the decomposition.
2nd. The continuous production of chlorine by passing as above
described a current of hydrochloric acid gas and atmospheric air, by
preference in a heated condition, over heated substances, porous or

page_text: otherwise, which are impregnated or mixed with metallic compounds,
such as are herein-before mentioned and described.
In witness whereof, I, the said Henry Deacon, have to this my
Specification set my hand and seal, the 24th day of October
One thousand eight hundred and sixty-eight.
HENRY DEACON. (L.S.)