IMPROVEMENTS IN THE PROCESS OP MAKING GAS FOR ILLUMINATING HEATING, AND OTHER PURPOSES. AND IN APPARATUS FOR THE MANUFACTURE THEREOF
Year: 1869

page_text: LETTERS PATENT to Henry Holdrege, of the City and State of New
York, United States of America, Gas Engineer, for the Invention of
"IMPROVEMENTS IN THE PROCESS OP MAKING GAS FOR ILLUMINATING
HEATING, AND OTHER PURPOSES. AND IN APPARATUS FOR THE MANUFACTURE
THEREOF."-Partly a communication from William Henry Gwynne,
residing at said New York, and George Washington Harris, residing
at Elizabeth, State of New Jersey, United States.
Sealed the 9th October 1869, and dated the 31st May 1869.
PROVISIONAL SPECIFICATION left by the said Henry Holdrege at the
Office of the Commissioners of Patents, with his Petition, on the
31st May 1869.
I, HENRY HOLDREGE, of the City and State of New York, United
States of America, Gas Engineer, do hereby declare the nature of the said
Invention for IMPROVEMENTS IN THE PROCESS CF MAKING GAS FOR ILLUMINATING,
HEATING, AND OTHER PURPOSES. AND IN APPARATUS FOR THE MANUFACTURE
THEREOF," the result partly of a communication made to me from William
Henry Gwynne, a person resident at said New York, and George Wash-
ington Harris, a person resident at Elizabeth, State of New Jersey,
[Price 8d 1

page_text: United States, and partly of Invention and discovery made by me, to be
as follows:
This Invention consists in an improvement in the process and
apparatus for thorough and rapid decomposition of steam into hydrogen
and carbonic oxide gases, and (when illuminating gas is to be produced)
their subsequent enrichment by hydrocarbons in other retorts charged
with bituminous coal or other material. I thus obtain a more desirable
product in the decomposing retort and a better chemical union of these
gases with those formed in the carbon retorts. The decomposing retort
is made of fire-clay of close texture and tenacious quality, such as found
in some German and similar clays, so that in manufacturing the retort
the clay in the kiln will have a tendency to flux instead of forming a
porous and brittle compound liable to disintegration. The retort may
have a false or double bottom, or is provided with hollow grooved tiles
lying upon its floor, and it is so constructed that steam may be introduced
under such false bottom or into the front tiles near the mouth piece of
the retort and flow to the back end, and after being superheated escape
into another retort through small apertures in the bottom or tiles; the
superheated steam is thus distributed in fine jets under the bed of
incandescent coal. This retort is charged with American anthracite coal
broken into pieces of the size of an egg. In combination with such
retort there is a steam superheater placed horizontally in the hotter parts
of the oven and forming part of the setting of the bench of retorts; it is
so constructed that steam admitted at the front end flows backward and
then returns to the front, where it passes to the superheating and
distributing chamber or tiles lying on the floor of the retort. In
connection with such superheater is a steam drier placed near the base
of the oven where the heats are quite moderate, and which consists of a
pipe enclosed within a larger pipe, the former being perforated with fine
holes through which the steam escapes, and being deprived of its super-
abundent moisture by contact with the heated and drying surfaces passes
to the superheater, where it is more thoroughly superheated before
its introduction into the retort for final superheating and distribution.
In making gas by decomposing water or steam by the aid of incan-
descent metal or carbonaceous material it has been the practise to
introduce the steam or water itself by a pipe into some part of the retort,
into which it issues in a stream or volume according to the diameter
of the pipe, thus bringing water as such or steam holding water in

page_text: mechanical suspension and far below the temperature required for
decomposition into carbonic oxide and hydrogen gases, producing
carbonic acid gas and lowering the temperature of the retort. thus
involving an unsteady and unsatisfactory flow of gases resulting from
the more or less imperfect decomposition of water and serious loss in the
whole process, and when more efficient means have been employed the
steam has not been superheated before entering the retort to the
temperature of the material within the retort and then properly
distributed among the surfaces of the incandescent charge within. The
other retorts of the bench are furnished with bituminous coal or other
material in the ordinary way.
My process is as follows:-The decomposing and other retorts being
charged as above steam from a boiler or generated in the bench is intro-
duced into the steam dryer, passing thence to the superheater and thence
to the channels of the false bottom or tile flooring of the decomposing
retort, where having been previously highly superheated it is further
heated and then distributed in fine jets among the mass of incandescent
anthracite coal. The retcrt being kept at a high heat the effect
produced is the immediate decomposition of the steam without reduction
of the temperature of the retort or of the anthracite coal, thus securing
a constant supply of the desired gases. These gases pass through a
conducting pipe (the decomposing retort having no stand pipe), into the
mouth pieces of the bituminous coal retorts, where they meet and mingle
with the gases illuminated from the coal or material in such retorts before
these reach the point of condensation in the hydraulic main. The gases
from the decomposing retort may be supplied to one carbon retort until
the rich carl on vapors pass off, and then be shut off by a cock and
turned into another retort for an equal length of time, the two retorts
being charged separately at intervals, and their charges being distributed
during the last one or two hours without any supply of hydrogen.
When a gas for heating purposes is to be produced the carbon or bitu-
minous coal retorts need not be used in connection with the hydrogen or
decomposing retort, but the latter with the saperheater and steam dryer
will alone be operated, and the gas produced conducted therefrom to
the gas holder through the usual condensers and purifiers.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Henry Holdrege in the Great Seal Patent Office on
the 29th October 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
HOLDREGE, of the City and State of New York, United States of America,
Gas Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirty-first day of May, in the year of
our Lord One thousand eight hundred and sixty-nine, in the thirty-
second year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto ine, the said.Henry Holdrege, Her special licence that 1.
the said Henry Holdrege, my executors, administrators, and assigns, or
such others as I, the said Henry Holdrege, my executors, administrators,
and 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 PROCESS OF MAKING
GAS FOR ILLUMINATING. HEATING, AND OTHER PURPOSES, AND IN APPARATUS FOR THE
MANUFACTURE THEREOF," the result partly of a communication made to me
from William Henry Gwynne, a person resident at said New York, and
George Washington Harris, a person resident at Elizabeth, State of New
Jersey, United States, and partly of Invention and discovery made by
me, upon the condition (amongst others) that I, the said Henry Holdrege,
my executors or administrators, by an instrument in writing under my,
or their, or one of their hands and seals, 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 T, the said Henry Holdrege, do hereby declare
the naturo of the said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by
the following statement:-
This Invention consists in an improvement in the process and
apparatus for the thorough and rapid decomposition in one or more
retorts of steam into hydrogen and carbonic oxide gases, and (when

page_text: illuminating gas is to be produced) their subsequent enrichment by
hydrocarbons in other retorts charged with bituminous coal or other
suitable material, and by means of such improved process and apparatus
there is obtained a more desirable product in the decomposing retort
and a better chemical union of the gases there formed with those formed
in the carbon retorts.

page_text: of about the size of an egg. In combination or connection with such
decomposing retort is a superheater E, a sectional view of which is
shown in Figure 6, which is made of a material similar to that used
for the said retort and so constructed that steam entering at the outer
end flows backward through a passage or channel and then through
a return channel to the front, whence it passes from ' to the super-
heating and distributing tiles D lying on the floor of the retort A.
Such superheater is placed horizontally in the hotter parts of the oven
and forms part of the setting of the bench. In connection with such
decomposing retort and superheater there is also a steam dryer F,
shown in section in Figure 5, which consists of a double pipe or tube
or oue small tube within a similar but larger pipe e and which are
made of iron or other suitable material, the inner pipe or tube, and
which receives the steam, being pierced with numerous fine holes 2, 2,
through which the steam escapes into the outer pipe, from which it
is conducted to the superheater before mentioned. The steam by its
contact with the heated surfaces of the pipes and a is deprived of
its superabundant moisture before it passes to the superheater, where it
is more thoroughly superheated before passing to the retort A. This
steam dryer is placed near the base of the oven and where the heats are
quite moderate.
In the operation of making gas by the decomposition of water or
steam by the aid of incandescent metal or carbonaceous material it has
been the practice to introduce the steam or water itself by means of a
pipe into some part of a retort, the retort containing the decomposing
substance, through one or more openings in a stream or volume
according to the diameter of the pipe, thus bringing water as such or
steam holding water in mechanical suspension, and far below the tem-
perature required for decomposition into carbonic oxide and hydrogen
gases, thereby producing carbonic acid gas, and also lowering the tem-
perature of the retort by abstracting the heat needful for evaporation
of wet steam and water. thus involving an unsteady and wholly
unsatisfactory flow of gases resulting from the more or less imperfect
decomposition of water, and involving serious loss in the whole process.
And even when more efficient means than those just described have
been resorted to, the steam has not been superheated before entering the
retort to the temperature of the incandescent material within the retort.
and then properly distributed through the surfaces of the incandescent

page_text: charge within. The efforts thus formerly made to produce a thorough
and rapid decomposition of steam into its elements have proved hitherto
abortive, and the product of carbonic acid has been so large as to nullify
any advantages gained. All these objections are overcome and removed
by the use of the perforated bottom in combination with the superheater
and dryer before described.
The retorts B and C are charged with bituminous coal or other suitable
material in the ordinary way. The operation or process is as follows:-
The decomposing retort A being charged with anthracite coal, and the
other retorts B and C with bituminous coal or other suitable material,
steam either from a boiler or generated by the heat of the oven is intro-
duced into the inner tube of the steam dryer F, and passes thence to
the superheater E, and from thence to the channels of the tile flooring D
of the decomposing retort, where having been previously highly super-
heated it is still further heated, and then distributed by means of the
small apertures in such tiles in fine streams among the mass of incau-
descent anthracite coal lying over and above such tile flooring. The
decomposing retort being kept at a high heat the effect produced is the
immediate decomposition of the steam without reduction of the tem-
perature of the retort or of its contents, thus securing a constant supply
of the desired gases.
The gases thus obtained from the retort A,
such retort not being provided with the ordinary stand pipes, through
the pipes f, f, into the mouth pieces of the bituminous coal retorts B, C,
where they meet and mingle with the vapors and gases eliminated from
the coal or other suitable gas yielding substance before these reach the
point of condensation in the hydraulic main. The gases from the decom-
posing retort are supplied to one carbon retort until the rich carbon
vapors pass off, when they are shut off by a cock 3 and turned into the
second or another carbon retort for the necessary time, or until its
rich carbon vapors pass off; the carbon retorts being charged separately
at intervals of, say, two hours, and their charges being distilled during
the last one or two hours without any supply of the gases from the
decomposing retort.
It is found that although hydrogen gas is produced in the first or
decomposing retort in excess of what would be required in the com-
position of a good carburetted hydrogen illuminating gas, yet the
completed gas (that is, the united gases from the steam and carbon
retorts when mingled as herein described) is proved by analysis to

page_text: contain no excess of hydrogen, and demonstrating the fact that the
hydrogen and carbonic oxide obtained from the decomposition of watery
vapor furnish to the nascent and distilling hydrocarbon vapors of the
bituminous coal retorts a most appropriate substratum for a permanent
illuminating gus of high quality, enriched by and obstinately clinging to
the illuminants lost by the common process in the coal tar, producing
even from common caking coals, and yet more from richer coals, a
largely increased value of total economical effect at a very unimportant
increase of cost, the gas thus produced much exceeding ordinary coal gas
in its purity and in its power to withstand without sensible loss of
illuminating power long continued exposure to low temperature.
The arrangement of the valves 3 in the connecting pipes f, f, also
permits each carbon retort to be entirely shut off from the other retorts
when desired. As the high heat of the pipes f, f, tends to greatly
expand the valves 3, 3, these valves are best made tapering or conical,
such shape rendering it both easy to tighten them in their seats, and also
remove them when necessary.
If instead of the common caking coals rich cannel coals are used in
the carbon retorts a more copious or longer supply of gases from the
hydrogen or decomposing retort will be necessary. And if instead of
one hydrogen or decomposing retort and two bituminous coal retorts the
bench be composed of five or six retorts, two of which will be hydrogen
retorts, the operation will be substantially the same.
The tile D is formed with both a bottom and a top surface, between
which are the steam channels or conveyors h, h. The steam thus does
not come in contact with the retort itself, and, therefore, if by any
accident the bottom of the retort should become cracked the steam
would not escape or the operation be seriously interfered with.
The decomposition of water or the vapor of water for the purpose of
obtaining non-luminous and combustible gases is not claimed; but there
is claimed as follows:-
The process of the manufacture of heating and illuminating gases by
decomposing highly heated and finely divided jets of steam by means of
anthracite coal, substantially as described.
The combination of the decomposing retort having a channelled,
grooved, or flued flooring of perforated tiles of fire-clay or other suitable
material with a steam superheater and steam dryer for the purpose of

page_text: drying and superheating and distributing the steam or vapor of water,
arranged and combined substantially as set forth.
The use of a fire-clay retort for holding and heating the decomposing
material for the purposes set forth.
The use and application of the valves or stop-cocks in the pipes
connecting the hydrogen or decomposing retorts with the carbon retorts
for the purposes set forth.
The form and construction of the steam receiving and distributing
tile, substantially as described.
In the process of manufacturing illuminating gas the mode of
obtaining a more perfect gas and a more uniform mixture of gases,
eliminated from coal and steam or their equivalent in separate retorts,
by supplying the hydrocarbon gas retorts with gas that are eliminated
from the vapor of water in a separate retort by passing steam super-
heated to about the temperature of the incandescent decomposing
material in a finely divided state through the mass of such decomposing
material, substantially as and for the purposes set forth.
In witness whereof, I, the said Henry Holdrege, have hereunto
set my hand and seal, this Thirtieth day of July, in the year
of our Lord 1869.
HENRY HOLDREGE. (L.S.)