IMPROVEMENTS IN THE MANUFACTURE AND PURIFICATION OF GAS, AND IN THE APPARATUS EMPLOYED THEREIN AND CONNECTED THEREWITH
Year: 1872

page_text: PROVISIONAL SPECIFICATION left by George Henry Carne Hedley,
William Smith, and Tom Abercrombie Hedley at the Office of
the Commissioners of Patents, with their Petition, on the 7th
November 1872.
We, GEORGE HENRY CARNE HEDLEY, WILLIAM SMITH, and Tom
ABERCROMBIE HEDLEY, all of No. 19, Salisbury Street, Strand, London,
do hereby declare the nature of the said Invention for "IMPROVEMENTS
IN THE MANUFACTURE AND PURIFICATION OF GAS, AND IN THE APPARATUS EMPLOYED
THEREIN AND CONNECTED THEREWITH," to be as follows:-
:-
Instead of using horizontal retorts, as is usual where the distillation
of coal and other materials used in combination therewith is carried on
in the ordinary manner, and instead of vertical retorts, or retorts set
vertically and having a foot or horizontal branch or continuation formed
at the bottom thereof for the purpose of discharging the solid deposit
produced in the manufacture of gas from oils or other hydrocarbons,
whether such vertical retorts be used with oil alone or in combination
with water, we employ retorts placed or set at an angle of about 45
degrees, the inferior end of which is enclosed by a mouth piece, and the

page_text: superior end is fitted with a mouth piece or charging box having a valve
fitted thereinto or thereunto for the rapidly opening and closing the
communication with the retort; the mouth piece or valve at the
inferior end should be of the same size as the largest section of the
retort so as to discharge the materials contained therein freely. The gas
as generated is by preference drawn off or permitted to escape or be
discharged from the upper side of the inferior end of the retort.
We prefer for small gas generating works to construct the retort
or retorts with one or more divisions axially or vertically, to receive the
several materials employed for generating and purifying the gas; or
instead of a division or divisions in each retort, we prefer in many cases
to combine together several retorts in such a manner, by junction
pipes and valves or suitable connections, as to effect the same purpose
of purifying or depuritating the gas as it is generated, and by which the
tar distilled from the coal in one retort or in one division of a retort,
is utilised and converted into gas, and instead of making the retorts of
a uniform vertical section and dimensions we prefer in most cases that
they shall be of greater area at the lower end either by an enlargement
gradually decreasing upwards, or where several retorts are intended to
be connected together, there may be an enlargement of the inferior end
below or beyond the action of the fire; grids of fire-clay may be
introduced at the lower portions or parts of a retort to hold purifying
materials, and in such case at the upper ends of such retorts a junction
or connection with the cooling apparatus may be made instead of such
junction being made at the inferior end, and as in other cases we prefer
it should be so that the gas as generated from the coal oil (or other
material or materials used in combination) is made to pass through or
over the purifying materials, and also effects the mixing of the gases as
they are generated, or in a nascent state before escaping from the
generator to the cooler and other vessels.
The outlet pipe from the retort or retorts is to have a hydraulic valve
made to act in place of the hydraulic main in common use, and
immediately the gas generated passes through it to be cooled by a
jacket or casing the pipe leading from the valve is to have an inclination
back towards the retort, so that in case of any tar or liquid, or
condensible vapour escaping from the retort (or passing therefrom) shall
be at once condensed and returned to the retort, there to be converted
into inflammable gas.

page_text: In some cases the inclined retort may have a vertical or horizontal
branch therefrom to which the outlet or discharge pipe may be
connected outside the retort setting or furnace work, and such branched
portion may contain the purifying materials and receive the secondary
action of the fuel.
For the condenser or condensing apparatus we prefer an annular
arrangement placed nearly horizontally, or at a suitable inclination.
In constructing purifiers or purifying vessels we prefer that they
should be made with divisions and that doors or covers or means of
access should be by means of removeable ends having ground faces, and
made gas tight by means of the ordinary luteing or gastret, thus doing
away with the usual water joint or top cover and lute.
In most cases we prefer setting the retors so that the arrangement of
the flues, the principal body of heat is concentrated upon that part of
the composite retort holding the materials for generating the gas,
leaving the spent or secondary heat to act upon that part of the retort
containing the purifying materials; and where two (or more) retorts aré
employed in combination instead of a composite or divisional retort, we
in a similar manner, and for like purpose suitably design and arrange
the furnace and flues or heat passages to effect the same objects. The
gas or gases, as it or they are generated from one or from several
materials being compelled to pass over and through amongst the
purifying materials at a suitable temperature.
For the purification of the gas as generated, or as generated and
combined within the retort or retorts, we propose to employ a com-
position or mixture of scrap iron or iron ore with spent tanners' bark,
charcoal or coke, or equivalent materials, and mixed with lime either in
a dry or moist state; those after having been mixed tegether in proper
proportions are suitable disposed either within a portion of a retort or
upon grids, or in a separate but connected retort, so that the gas as
generated is passed through and amongst the purifying materials and is
deprived of its sulphuretted hydrogen and other sulphur compounds, and
whereby also the tarry and other vapours produced from the distilling
process are converted into gas, and thus the quantity, purity, and
illuminating power of the gas generated from a given quantity of coal or
other material is greatly increased.

page_text: For charging purifiers or purifying vessels we employ in most cases
refuse or spent tan in addition to the lime and other well known
materials used or employed in the purification of gas for illumination,
by which we deprive the gas first of its ammoniacal compounds, and
thereby effecting economy in the use of lime and depriving it of its
noxious vapour, causing the gas when distributed or stored to be freer
from sulphur compounds in any shape than is obtainable by the
ordinary processes of gas purification.
For gas generating on a small scale, as for lighting mansions, mills,
and factories, and as a substitute for coal, we propose to employ a
mixture of oil and fatty matters, and the waste or refuse from domestic
kitchens mixed with sawdust, spend tan or tanners' bark, and such like
materials roughly moulded into small masses; and where crude, mineral
oils, petroleum, and other suitable liquid hydrocarbons can be cheaply
obtained, we prefer to employ in combination therewith and within the
same retort a jet of steam, if such is easily obtainable, admitted under
regulation by means of a cock or valve, by which substitution of steam
the cooling down of the retort in the process of making gas from oils is
prevented, and the more uniform production of a permanent illuminating
gas is more economically effected. In the combined retorts as in the
compound retort, limestone may in some cases be employed in com-
bination with the other materials for the purification of the gas whilst
being generated and passed off.