IMPROVEMENTS IN THE MANUFACTURE AND PURIFICATION OF GAS FOR ILLUMINATION, AND CERTAIN PRODUCTS THEREFROM, AND I APPARATUS FOR THAT PURPOSE
Year: 1852

page_text: PROVISIONAL SPECIFICATION left by Jean Marie Souchon at the
Office of the Commissioners of Patents, with his Petition, on the
22nd October 1852.
(Void by reason of notice to proceed not having been given within the
time prescribed by the Act.)
I, JEAN MARIE SOUCHON, of Paris, in France, Chemist, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN THE
MANUFACTURE AND PURIFICATION OF GAS FOR ILLUMINATION, AND CERTAIN
PRODUCTS THEREFROM, AND I APPARATUS FOR THAT PURPOSE," to be as
follows:-
The gas obtained by the destructive distillation of coal or other
bituminous, carbonaceous, or nitrogenous matter is passed, together
with the tar and ammonia which accompany it, through a heated retort
containing potash or soda in a caustic state, or combined with carbonic
acid or other acid, and either alone or mixed with carbonaceous or
other substances. The potash or other alkali is agitated by an agitator
with a perforated disc at each end, inclosed in the retort so as
continually to expose a fresh surface; or it is mixed with charcoal or
other solid matter, so as to form a porous mass. In lieu of passing the
gas with the tar and ammonia through this retort, the tar and ammonia

page_text: may be passed through it without the gas. The effect of this operation
is to decompose a portion or the whole of the tar, and convert it into
gas, and also to produce a quantity of cyanide or ferrocyanide of
potassium or sodium, which is afterwards extracted and crystallized or
used in the production of other compounds of cyanogen. The gas on
leaving this retort passes through a stuffing box or other joint into
a series of revolving purifiers. These consist of cylindrical or other
vessels filled with small branches of wood or other solid matters having a
multitude of interstices between them for the passage of the gas. These
vessels are partially filled with purifying liquid, so that as they revolve
the pieces of wood become wetted by the liquid, and are then exposed
to the gas. A portion of the liquid is also raised by a gutter or scoop,
and poured upon the wood by the motion of the vessel. Four vessels or
a greater or less number may be employed. The first contains sulphate
of lime in suspension in water, and serves to decompose and fix the car-
bonate of aminonia contained in the gas. The second contains a solution
of sulphate of iron or other metallic salt, and serves to absorb some or
all of the sulphuretted hydrogen and ammonia. The third contains a
solution or cream of lime to absorb the carbonic acid, and any remain-
ing sulphuretted hydrogen. The fourth purifier contains dilute sulphuric
or muriatic acid to absorb ammonia. The gas then passes through a
hydraulic valve to the gasometer. Other purifying liquids, or the same
liquids in different order, may be employed in the same apparatus. A
hydraulic valve is connected to the pipes from the gas retorts, by means
of which the gas may be shut off from the purifiers while they are
being charged. It is then directed into another similar apparatus, or
into the ordinary hydraulic main and purifying apparatus when the im-
proved apparatus is applied to a gas work already in operation with
such ordinary apparatus. By these arrangements the pressure on the gas
in the retorts may be reduced to that of the gasometer, while the
advantages of wet purifiers are obtained without increasing the pressure
in the retorts.
The retort which contains the alkali is closed by means of a door
hung upon binges with elliptical or elongated holes, so that it may be
pressed up against the face by means of four latches or catches which

page_text: act upon inclined planes on the door, and force it against the mouth of
the retort. This construction of door is applicable to other retorts as
well as to that which contains the alkali.
In lieu of conveying the gas into the alkali retort, the retort may be
supplied with the vapour of tar and ammonia, by dropping or injecting
the same into a heated retort of a crescent form in section, with a fire
within or under it, or in a retort of any other suitable form. Ammonia
or nitrogenous substances may be mixed with the tar so employed, and
in some cases a fixed alkali may also be added.
Compounds of cyanogen sometimes pass into one or more of the
purifying vessels, and may be separated by precipitation with iron or
otherwise.