IMPROVEMENTS IN AND RELATING TO THE MANU- FACTURE OF CHLORINE
Year: 1884

page_text: I, WALTER WELDON, of Rede Hall, Burstow, Surrey, Fellow of the Royal
Society, President of the Society of Chemical Industry do hereby declare the
nature of the said invention for IMPROVEMENTS IN AND RELATING TO THE MANU-
FACTURE OF CHLORINE, a communication from A. R. Pechiney, et Cie., of Salindres,
in the Department of Gard, in the Republic of France, to be as follows:-
The present invention relates to the various systems of manufacturing chlorine
in which chlorine is liberated from a chloride of a metal, or from a mixture of two
or more chlorides of metals, by heating such chloride or mixture of chlorides in
contact with atmospheric or other oxygen, the said chloride or chlorides being so
heated in contact with oxygen either alone or in admixture with an oxide or with
two or more oxides, such as inagnesia, oxide of manganese, oxide of iron, alumina,
silica, or others.
The said invention consists in effecting the operation of heating such chlorine
yielding substances in presence of atmospheric or other oxygen by placing the said
substance or mixture of substances in receptacles formed by a suitable arrangement
and disposition of masses of brick-work or other suitable material, which masses of
brick-work or the like have previously been heated to a sufficient temperature by
contact with hot products of combustion or other hot gas or gases which have been
caused to traverse the interior of the said receptacles, but the admission of which
thereinto has been suspended before the said receptacles are charged' with the
substance or mixture of substances froin which it is desired to drive off chlorine by
the action upon them at a high temperature of atmospheric or other oxygen, the
said substance or mixture of substances being then heated at the expense of the
heat previously stored up in the masses of brick-work constituting the walls, sidės,
and floors of the said receptacles.
"
An apparatus for carrying out this method of heating the said substance or
mixture of substances is shown in the accompanying sheet of drawings. Figure 1
is a vertical section showing four vertical chambers A, A1, A2, and A³. These
chambers of small diameter, but their walls or partitions are relatively thick. The
four chambers communicate with each other, alternately at their upper and at
their lower extremities, so that gases entering at the bottom of chamber A can pass
from the top of chamber A into chamber A, then from the bottom of chamber A¹
into the lower part of chamber A³, then from the upper part of chamber A² into
chamber A³, and then from the bottom of chamber A³, according to circumstances,
as will be hereinafter explained, either through the pipe M¹, or into and through

page_text: :
one of the two regenerators, I, I, and IV, I, and thence to a commney.
evident from the drawing that gases can equally traverse the apparatus in the
contrary direction, and in working the apparatus it will be convenient that they
should traverse it in the one direction and in the other alternately. The substance
or mixture of substances to be heated in these chambers is introduced thereinto by
the openings at B, B, B, B, which openings can be closed at will by suitable covers,
and the residual contents of the chambers are afterwards discharged by doors
at c, c, c, c. The openings d, d, d, d, which, like B, B, B, B, and c, c, c, c, are
capable of being opened and closed at will, are for the purpose of enabling the
interior of the chambers to be seen into when required, and also for the introduction
when need be of tools by which to facilitate the operation of discharging the
chambers.
The regenerators R, R, and R, R, are not essential to the apparatus; but their
employment will usually be advantageous.
Figure 2 is a section across the line C, D, of Figure 1, and Figure 3 is a section
across the line A, B, of Figure 1. The same letters refer to the same parts in all
the figures.
As will be well understood, an apparatus constructed according to this invention
should preferably be encased externally by iron plates, coated with some non-
conducting substance.
.
In working this apparatus, the first step will be to heat the four chambers, A, A',
A2, and A. We will suppose that the fuel employed is gaseous fuel, and that in
the operation of heating up the apparatus for the first time that gaseous fuel is
admitted into one of the compartments of the regenerator on the side C of
Figure 1, and the air to burn it into the other compartment of that one of the two
regenerators. The pipes M. and M¹ being closed, products of combustion will enter
the bottom of chamber A, and will traverse successively chambers A1, A2, and A³,
passing off by the regenerator on the side D of Figure 1.
When the masses of
brick-work or other material constituting the sides, top, and bottom of the four
chambers A, A1, A2, and A³ have absorbed a sufficient quantity of heat, the
admission of gaseous fuel will be suspended, and the chambers will be charged, by
the openings at B, B, B, B, with the substance or mixture of substances from which
chlorine is to be driven off by the reaction upon that substance or mixture
of substances at a suitable temperature of atmospheric or other oxygen. The
regenerator by which products of combustion passed off from the apparatus while
it was being heated the first time will now be closed, and air only be admitted
through the other regenerator, the pipe M being kept closed, but communication
being opened with the pipe M1. The substance or mixture of substances charged
into the chambers A, A1, A2, and A³ will absorb heat from the masses of heated
brick-work or the. like forming the sides etc. of the said chambers, and a current of
air which has been previously more or less heated will pass over and through the
contents of the four chambers, and there will pass off by the pipe M¹ a mixture of
gases containing free chlorine. When the charge in the four chambers A, A1, A2,
and A³ has been in this way sufficiently decomposed, the residual solid product of
the reaction of oxygen on the substance or mixture of substances which was
originally charged thereinto will be discharged by the doors at c, c, c, c, the
pipes M and M¹ will be closed, and the apparatus will again be heated up as before,
except that this time the gaseous fuel and the air to burn it will enter by the
regenerator by which in the first operation of heating up the apparatus the
products of combustion which had traversed the apparatus passed off from it, and
that products of combustion will thus traverse the apparatus in the opposite
direction to that in which they then traversed it. When the apparatus has been
a second time sufficiently heated, the admission of fuel will be suspended as before,
the chambers will be again charged with solid substance capable of yielding free
chlorine on being heated in a current of air, but this time the apparatus will be
traversed by air in the direction A³ to A, a mixture of gases containing free
chlorine passing off by the pipe M.

page_text: In this description of the mode of working of an apparatus according to the
present invention, I have spoken of its being heated by means of gaseous fuel;
but it may be heated by the products of the combustion of any kind of fuel,
burnt in whatever kind of fire-place. And, as I have already indicated, it may
be worked either with or without regenerators; and the oxygen employed to react
upon the chlorine yielding substance or mixture of substances may be either
atmospheric oxygen or free oxygen from any other source.
The products of combustion which have traversed the apparatus should preferably
be employed for evaporative purposes before being allowed to pass to the chimney.
The chloride or chlorides from which free chlorine is to be obtained by heating it
or them in contact with oxygen will frequently be first obtained in aqueous
solution, which solution will require to be evaporated to dryness before such
chloride or chlorides can be subjected to the action of heat and air, and the said
products of combustion may conveniently be used in such case for evaporating the
said solution of such chloride or chlorides.
The mixture of gases containing free chlorine which passes off by the pipes
M and M may in some cases contain vapour of hydrochloric acid. In such case,
as will be well understood, the said mixture of gases, before passing on to the
apparatus in which its chlorine is to be utilized, should be passed through apparatus
in which the vapour of hydrochloric acid at first associated with it may be
condensed out from it.
The apparatus which is above described and which is represented in the
accompanying sheet of drawings contains four receptacles in which to place the
substance or mixture of substances to be heated in contact with atmospheric or
other oxygen, and these four receptacles are placed vertically, but I do not confine
myself to the use either of any particular number of receptacles, or of vertical
receptacles. It is obvious that without departing from the principle of this
invention, the number of receptacles may be either greater or less than four, and
they may be arranged and disposed in a great variety of ways: as for example,
instead of vertically, either horizontally, or in an inclined position.
What is new in this invention thus consists in the above described system of
working, mode of procedure, and disposition of appliances for obtaining free
chlorine from a chloride of a metal, or from a mixture of two or more chlorides of
metals, the said chloride or chlorides being mixed or not with any other substance
or substances, but being capable, when heated to a sufficient temperature, either
alone or in admixture with such other substance or substances, as the case may be,
but in contact with atmospheric or other oxygen, of giving off free chlorine and
taking up oxygen instead, by which system of working and disposition of
appliances the substance or mixture of substances to be treated by heat and
atmospheric or other oxygen is treated thereby by being charged into suitable
receptacles, the walls or sides and other parts of which have been previously heated
by contact with products of combustion or other hot gases, which products of
combustion or other hot gases have been caused to traverse the interior of the said
receptacles, but the admission of which into the said apparatus has been suspended
before the chlorine yielding substance or mixture of substances is charged thereinto,
the said substance or mixture of substances being then heated to the requisite
temperature at the expense of the heat previously stored up in the walls, sides,
partitions, and other parts of the said receptacles, and atmospheric or other oxygen
being admitted thereinto during the operation, substantially by the means and
in the manner which are above described and which are illustrated by the
accompanying sheet of drawings.
Dated this twenty-first day of June 1884.

page_text: I, WALTER WELDON, of Rede Hall, Burstow, in the County of Surrey, Fellow of
the Royal Society, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN AND RELATING TO THE MANUFACTURE OF CHLORINE,"-a Communi-
cation from Messieurs A. R. Pechiney et Compagnie, of Salindres (Gard) in the
Republic of France, and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement :-
The present invention relates to the various systems of manufacturing chlorine
in which chlorine is liberated from a chloride of a metal, or from a mixture of two
or more chlorides of metals, by heating such chloride or mixture of chlorides in
contact with atmospheric or other oxygen, the said chloride or chlorides being so
heated in contact with oxygen either alone or in admixture with an oxide or with-
two or more oxides, such as magnesia, oxide of manganese, oxide of iron, alumina,
silica, or others.
The said invention consists in effecting the operation of heating such chlorine
yielding substance or mixture of substances in presence of atmospheric or other
oxygen by placing the said substance or mixture of substances in receptacles
formed by a suitable arrangement and disposition of masses of brickwork or other
suitable material, which masses of brickwork or the like have previously been
heated to a sufficient temperature by contact with hot products of combustion or
other hot gas or gases which have been caused to traverse the interior of the said
receptacles, but the admission of which thereinto has been suspended before the
said receptacles are charged with the substance or mixture of substances from
which it is desired to drive off chlorine by the reaction upon them at a suitable
temperature of atmospheric or other oxygen, the said substance or mixture of
substances being then heated at the expense of the heat previously stored up in the
masses of brickwork constituting the walls, sides, and floors of the said receptacles,
and while so heated subjected to the reaction of atmospheric or other oxygen.
An apparatus-for carrying out this method of heating the said substance or
mixture of substances in a current of atmospheric or other oxygen is shown in the
accompanying sheet of drawings. Figure 1 is a vertical section, showing four vertical
chambers A, A1, A2, and A³. These chambers are of small diameter, but their
walls or partitions are relatively thick. The four chambers communicate with each
other, alternately at their upper and at their lower extremities, so that, the pipe M
being closed, gases entering at the bottom of chamber A can pass from the top of
chamber A into chamber A¹, then from the bottom of chamber A¹ into the lower
part of chamber A³, then from the upper part of chamber A' into chamber A³, and
then from the bottom of chamber A³, either through the pipe M', or, if that pipe
be closed, into and through one of the two regenerators, R, R, and R, R, and thence
to a chimney. It will be evident from the drawing that gases can equally traverse
the apparatus in the contrary direction, and in working the apparatus it will be
convenient that they should traverse it in the one direction and in the other
alternately, especially the hot gases used for heating the apparatus. The substance
or mixture of substances to be heated in these chambers is introduced thereinto by
the openings.at B, B, B, B, which openings can be closed at will by suitable covers,
and the residual contents of the chambers are afterwards discharged by, doors at
c, c, c, c. The openings d, d, d, d, which, like B, B, B, B, and c, c, c, c, are capable of
being opened and closed at will, are for the purpose of enabling the interior of the
chambers to be seen into when required, and also for the introduction when need
be of tools by which to facilitate the operation of discharging the chambers.
The regenerators, R, R, and R, R, are not essential to the apparatus; but their
employment will usually be advantageous. It will be well understood that the

page_text: regenerators need not necessarily be placed in the position in relation to the other
part of the apparatus in which they are shown in Figure 1 of the accompanying
sheet of drawings. They may be placed either below the other part of the
apparatus, or above it, or on the same level therewith, as may be preferred or may
be more convenient in each particular case.
Figure 2 is a section across the line C, D, of Figure 1, and Figure 3 is a section
across the line A, B, of Figure 1. The same letters refer to the same parts in all
the figures.
It will be well understood that an apparatus in accordance with this invention
should preferably be encased by iron plates, and be protected as far as practicable,
by any convenient means, from loss of heat by radiation.
The fuel used for heating an apparatus according to the present invention may
either be gaseous fuel, or any kind of solid or liquid fuel burnt in any convenient
fire-place from which the products of its combustion can be passed into and through
the working chambers of the said apparatus. It will usually, however, be most
convenient to employ gaseous fuel; and the disposition of apparatus represented in
the accompanying sheet of drawings is one adapted for the use of gaseous fuel.
The apparatus according to this invention which is represented in the accom-
panying sheet of drawings contains four receptacles or chambers in which to place
the substance or mixture of substances to be heated therein, and these receptacles
are all placed vertically. My correspondents, however, do not confine themselves
to the use either of any particular number of such chambers or receptacles, or to
the use of vertical chambers or receptacles. It is obvious that without departing
from the essential nature of their invention the number of chambers or receptacles
may be either greater or less than four, and that they may be arranged and disposed
in a variety of ways: as, for example, instead of vertically, either horizontally, or
in an inclined position.
In the disposition of apparatus shown in Figure 1 of the accompanying sheet of
drawings, the gases enter the four chambers or receptacles, A, A1, A2, A³, at the
bottom of A or of A³, and pass off from the bottom of As or of A; but the
dispositions of the dividing walls may obviously be so modified that the gases shall
enter at the top of A or of A³, and pass off from the top of As or of A, or that they
may enter at the top of one chamber and pass off at the bottom of it or of another
chamber, and vice versa, according to the number of chambers employed.
In working an apparatus according to this invention, say, for example, an
apparatus disposed as is represented in the accompanying sheet of drawings, the
first step is to heat up the four chambers or receptacles, A, A1, A2, A³. To this
end, gaseous fuel is admitted by one of the two divisions, and air to burn it by the
other of the two divisions, of one of the two regenerators, R, R, and R, R. The
pipes M and M¹, the doors c, c, c, c, the covers above B, B, B, B, and the sight-
holes d, d, d, d, being all closed, products of combustion then traverse each of the
four chambers successively, and finally pass off by the other of the two regenerators,
from which they are conducted to a chimney. In order that the furnace shall be
heated uniformly, it will usually be best that the gaseous fuel and the air to burn
it should enter the apparatus, during this operation of heating it, first by one of
the two regenerators and then by the other, the alternations being repeated more
or less frequently. When the masses of brickwork or other material constituting
the sides, etcetera, of the four chambers or receptacles, A, A1, A2, A3, have absorbed
a sufficient quantity of heat, the admission of gaseous fuel into the apparatus must
be suspended, and the chambers charged, by the openings at B, B, B, B, with the
substance or mixture of substances from which chlorine is to be evolved. The
openings by which the charge was admitted into the apparatus having been closed,
one of the two pipes, M and M', must now be opened, and the regenerator on the
same side of the apparatus closed, and air only be admitted by the other
regenerator. The substance or mixture of substances contained in the chambers or
receptacles, A, A¹, A³, and A³ will then absorb heat from the masses of brickwork
or other material forming the sides etcetera of the said chambers or receptacles, and

page_text: a current of air which has been previously more or less heated during its passage
through the regenerator by which it has been admitted will pass over and through
the contents of the four chambers, and there will pass off by that one of the two
pipes, M and M', which is on the side of the apparatus opposite to that by which
air is admitted into it a mixture of gases containing free chlorine. It will usually
be best that the air admitted into the apparatus during each operation should enter
'alternately by each of the two regenerators, the mixture of gases containing free
chlorine passing off from the apparatus alternately by the pipe M and by the
pipe M. When the charge in the chambers or receptables, A, A', A2, A3, has been
sufficiently decomposed, the residual solid product of the reaction of oxygen on the
substance or mixture of substances which was originally charged thereinto must ho
discharged by the doors c, c, c, c, and then, these doors, the pipes M and M', and
the sight-holes d, d, d, d, having been all closed, the apparatus will be ready to be
heated up again, for another operation.
The products of combustion which have been employed to heat up an apparatus
according to this invention should preferably be employed for evaporative purposes
before being allowed to pass to the chimney. The chloride or chlorides from which
free chlorine is to be obtained by heating it or them, in admixture or not with other
substances, in contact with atmospheric or other oxygen, will frequently be first
obtained in aqueous solution, which solution will require to be evaporated to
dryness before such chloride or chlorides can be subjected to the action of heat and
oxygen; and in such case the said products of combustion may conveniently be
used for evaporating the said solution of a chloride or of two or more chlorides.
The mixture of gases containing free chlorine which passes off by the pipes M
and M¹ may in some cases contain vapour of hydrochloric acid. In such case, as
will be well understood, the said mixture of gases, before passing on to the
apparatus in which its chlorine is to be utilized, should be passed through
apparatus in which the vapour of hydrochloric acid at first associated with it may
be condensed out from it.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, I declare that what
I claim is the above described system of working, mode of procedure, and
disposition of appliances for obtaining free chlorine from a chloride of a metal, or
from a mixture of two or more chlorides of metals, the said chloride or chlorides
being in the solid state and being mixed or not with any other substance or
substances, by which system of working and disposition of appliances the said
chloride or mixture of chlorides, mixed or not with other substance or substances,
is treated by heat and atmospheric or other oxygen by being charged into suitable
receptacles, the walls or sides and other parts of which have been previously heated
by contact with products of combustion or other hot gases, which products of
combustion or other hot gases have been caused to traverse the interior of the said
receptacles, but the admission of which into the said apparatus has been suspended
before the chlorine-yielding substance or mixture of substances is charged thereinto,
the said substance or mixture of substances being then heated to the requisite
temperature at the expense of the heat previously stored up in the walls, sides, and
other parts of the said receptacles, and atmospheric or other oxygen being admitted
thereinto during the operation, the said receptacles being placed either vertically
or horizontally, or in an inclined position, as may be most convenient in each
particular case.
Dated this 9th day of December 1884