IMPROVEMENTS IN THE MANU- FACTURE OF CHLORINE AND CHLORIDE OF LIME to be as follows:-
Year: 1884

page_text: I ERNEST SOLVAY of Brussels in the Kingdom of Belgium, Manufacturer, do
hereby declare the nature of said Invention for "IMPROVEMENTS IN THE MANU-
FACTURE OF CHLORINE AND CHLORIDE OF LIME to be as follows:-
"
In the specifications of Letters Patent granted to me in Great Britain dated
respectively the 8th of January 1877, No 77, for Improvements in the Manufacture
of Chlorine, the 25th of February 1880 N° 838 for Improvements in means and
apparatus for the decomposition of chloride of calcium in order to obtain there-
from hydrochloric acid and chlorine, and the 25th of February 1880 N° 839 for
Improvements in the manufacture of chloride of lime I described the process and.
apparatus employed by me in the manufacture of chlorine by means of chloride
of calcium. Since that time I have continued my researches and have invented
the improvements hereinafter described relating firstly to the decomposing
apparatus and secondly to the absorption of the chlorine by lime.
I. DECOMPOSING APPARATUS.
The difficulty of keeping the apparatus gas tight when it is made of pieces or
sections of fire proof materials is well known, and cast iron and iron are not well
suited to resist the action of chlorine and the high temperatures which are to be
attained in the operation.
I therefore cover the iron or cast iron with preservative coatings to preserve it
from internal or external oxidation.
With certain mixtures of soda, clay, and vitrifiable products, I have obtained
coatings capable of resisting high temperatures and which are not attacked by the
action of chlorine.
I sometimes add to this sort of enamel a fireproof coating which adheres to the
metal and forms part of it through the intermediary of the vitrified enamel. I also
apply in this special case the processes of inoxidation of iron which consist in
previously producing on the metal a very adherent layer of magnetic oxide which
is not attacked by chlorine.
The difficulty of keeping the apparatus gas tight when it is made of pieces or
sections of fire proof materials is well known, and cast iron and iron are not well
suited to resist the action of chlorine and the high temperatures which are to be
attained in the operation.
I therefore cover the iron or cast iron with preservative coatings to preserve it
from internal or external oxidation.
With certain mixtures of soda, clay, and vitrifiable products, I have obtained
coatings capable of resisting high temperatures and which are not attacked by the
action of chlorine.
I sometimes add to this sort of enamel a fireproof coating which adheres to the
metal and forms part of it through the intermediary of the vitrified enamel. I also
apply in this special case the processes of inoxidation of iron which consist in
previously producing on the metal a very adherent layer of magnetic oxide which
is not attacked by chlorine.

page_text: II. ABSORPTION OF THE CHLORINE BY LIME.
The chlorine which I obtain by this process is highly diluted in a great excess of
air and nitrogen, it is therefore a difficult question to cause the lime to absorb the
chlorine.
From the first I paid great attention to this matter and I have used a very
systematic mode of producing the absorption of the chlorine by filling up a tower
with little balls of agglomerated lime and then causing the gases containing chlorine
to pass up through the said balls fresh balls being supplied from time to time by the
top whilst the chloride of lime was withdrawn at the bottom.
The absorption was however still difficult and moreover as an article of commerce
chloride of lime is required to be in a state of powder; I have therefore endeavoured
to chloruret the pulverulent slacked lime directly by causing the gases containing
chlorine to pass through it systematically in the same way as in the preceding
case.
The process consisting in causing chlorine to pass through powdered lime bas
already been proposed in a vague and general manner but no details have been
given and no industrial application of it has been made. I have therefore had to
study this question thoroughly in all its details and I have resolved it satisfactorily
as follows: I lay down the lime in a layer of suitable thickness upon beds of porous
and pulverulent mineral matters, such as pebbles, silex, sand, mineral wool, in the
manner used for filtering certain liquids which attack vegetable fabrics.
But I prefer to use mineral fabrics such as asbestos cloth or other mineral
fabrics.
The lime beds are superposed systematically in a manner similar to that used in
the purification of illuminating gas..
The lime chambers may also be placed in succession one after the other; but in
all cases the chloruretted gases must pass down through the whole thickness of each
layer of lime and it is indispensable that the gases be made to pass downwards in
order that they may be equally distributed throughout the lime; when the gases.
are caused to traverse the lime in the opposite direction (that is upwards) channels
or flues are soon formed and the greater part of the gases escape through them and
are wasted and the chloruretting ceases to be regular and cannot be carried on to
the required extent.

page_text: The chlorine which I obtain by this process is highly diluted in a great excess of
air and nitrogen, it is therefore a difficult question to cause the lime to absorb the
chlorine.
From the first I paid great attention to this matter and I have used a very
systematic mode of producing the absorption of the chlorine by filling up a tower
with little balls of agglomerated lime and then causing the gases containing chlorine
to pass up through the said balls, fresh balls being supplied from time to time by
the top whilst the chloride of lime was withdrawn at the bottom.

page_text: The absorption was however still difficult and moreover as an article of commerce
chloride of lime is required to be in a state of powder; I have therefore endeavoured
to chloridize the pulverulent slacked lime directly by causing the gases containing
chlorine to pass through it systematically in the same way as in the preceding
case.
The process consisting in causing clilorine to pass through powdered lime has
already been proposed in a vague and general manner but no details have been
given and no industrial application of it has been made. I have therefore had to
study this question thoroughly in all its details and I have resolved it satisfactorily
as follows: I lay down the lime in a layer of suitable thickness upon beds of porous
and pulverulent mineral matters such as pebbles, silex, sand, mineral wool in the
manner used for filtering certain liquids which attack vegetable fabrics.
But I prefer to use mineral fabrics such as asbestos cloth or other mineral
fabrics.
7
The lime beds are superposed systematically in a manner similar to that used in
the purification of illuminating gas.
1
...
"
The lime chambers may also be placed in succession one after the other; but in
all cases the chlóridized gases must pass down through the whole thickness of each
layer of lime and it is indispensable that the gases be made to pass downwards in
order that they may be equally distributed, throughout the lime; when the gases
caused to traverse the lime in the opposite direction (that is upwards) channels
or flues are soon formed and the greater part of the gases escape through them.and
are wasted and the chloridization ceases to be regular and cannot be carried on to
the required extent..
are.
:
'
Having now particularly described..and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I.claim is
i
1. The application to the decomposing apparatus used in the manufacture of
chlorine, of vitrifiable and other coatings. more or less refractory and not attacked by
chlorine for the purpose of protecting the iron and cast-iron parts of the apparatus
substantially as described.
2. In the manufacture of chloride of lime the application of mineral porous or
pulverulent matters and particularly of mineral fabrics such as asbestos or other
mineral cloth to support the pulverulent layers of lime, in combination with the
passage of the chloridized gases through the lime.
3. The process which, in combination with the passage of the chloridized gases
through a number of successive layers of lime arranged systematically consists in
constantly bringing back the chloridized gases above each layer of slacked lime, so
that the said gases pass successively down through all the said layers.
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