IMPROVEMENTS IN THE TREATMENT OF LIQUID HYDROCARBONS FOR THE PURPOSE OF OBTAINING A PERMANENT GAS
Year: 1867

page_text: City of London, Civil Engineer, for the Invention of "IMPROVEMENTS IN
THE TREATMENT OF LIQUID HYDROCARBONS FOR THE PURPOSE OF OBTAINING A
PERMANENT GAS."
Sealed the 23rd August 1867, and dated the 28th February 1867.
PROVISIONAL SPECIFICATION left by the said Alexander Angus Croll
at the Office of the Commissioners of Patents, with his Petition, on the
28th February 1867.
I, ALEXANDER ANGUS CROLL, of Coleman Street, in the City of London, Civil
Engineer, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN THE TREATMENT OF LIQUID HYDROCARBONS FOR THE PURPOSE OF OBTAINING
A PERMANENT GAS," to be as follows:-
In order to obtain a permanent gas from liquid hydrocarbons I place the
liquid to be treated in a close vessel surrounded by a steam jacket heated by
steam, by which, or by other suitable heat, I raise the temperature of the liquid
to a boiling point and generate vapour; the vapour produced is then conducted
in contact with heated surfaces in a close chamber or retort highly heated, by
which the vapour will be converted into a permanent gas and may be conducted.
by suitable channels for use.

page_text: SPECIFICATION in, pursuance of the conditions of the Letters Patent filed
by the said Alexander Angus Croll in the Great Seal Patent Office on
the 28th August 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
ANGUS CROLL, of Coleman Street, in the City of London, Civil Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her. Letters
Patent bearing (late the Twenty-eight day of February, in the year of our Lord
One thousand eight hundred and sixty-seven, in the thirtieth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Alexander Angus Croll, Her special licence that I, the said Alexander
Angus Croll, my executors, administrators, and assigns, or such others as I,
the said Alexander Angus Croll, 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." In-
PROVEMENTS IN THE TREATMENT OF LIQUID HYDROCARBONS FOR THE PURPOSE OF
OBTAINING A PERMANENT GAS," upon the condition (amongst others) that I,
the said Alexander Angus Croll, 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 I, the said Alexander Angus Croll, do hereby declare
the nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof, that is to say:-
.
In order to obtain a permanent gas from liquid bydrocarbons I place the
liquid to be treated in a close vessel surrounded by a steam jacket heated by
steam, by which, or by other suitable heat, I raise the temperature of the liquid
to a boiling point and generate vapour; the vapour produced is then conducted
in contact with heated surfaces in a close chamber or retort highly. heated, by
which the vapour will be converted into a permanent gas and may be conducted
by suitable channels for use.
In carrying out my improvements the liquid hydrocarbons I select to operate
upon are such as may be vaporized at a temperature under 230° Fahrenheit,

page_text: but in using coal tar the temperature may be increased, limited only by the
tendency of such matter to the developement of napthaline. Such liquid I
prefer to conduct from a suitable reservoir by a pipe or tube into a first
converting chamber which may be of the form of a horizontal boiler, the
conducting pipe or tube being introduced into this chamber at one end of it,
and being supported in the interior thereof to near the opposite end where the
liquid bydrocarbon is allowed to flow into this first chamber, which chamber
may be heated either by steam acting to the desired temperature in a
surrounding jacket or otherwise. At the opposite end of this chamber to
that of the supply thereto of the hydrocarbon liquid, and at the lower part
thereof, there is an outlet passage from which may be drawn off the residuum
of tar or other matter.
In carrying on the process with hydrocarbon liquid, such as coal tar,
obtained in the manufacture of gas from highly bituminous coal which freely
developes napthaline; and in order to avoid such developement of napthaline
during working, I consider it of importance so to control the heat to this
first converting chamber that the heat imparted to the contained liquid hydro-
carbon may not exceed 230° Fahrenheit. In working with other description
of coal tar not having such tendency to develope napthaline, the temperature
may be increased until a useful quantity of vapour ceases to be produced,
regard being had to the value of the remaining product. The vapour generated
in this first converting chamber is by a simple outlet passage conducted therefrom
into contact with heated surfaces in a close chamber or retort highly heated, or
heated to an extent that such second chamber or retort will be of a red color
dimly visible in the dark.
Should the nature of the hydrocarbon for the time under operation be such
that either a large or a less amount of heat may be found necessary in its
treatment, then the useful heat to be employed may readily be ascertained by
the following test:-When a deposition of solid carbon is formed in the
passage of the gas from the decomposer or heated chamber or retort, too
much heat has been employed and it must be reduced. When there is
condensation of a considerable portion of liquid hydrocarbon, too little heat
is being employed and it must be increased. The gas obtained by these
means may either be used alone or in combination with coal gas; when used
in the manufacture of coal gas it will enable the manufacturer to obtain an
increased produce of gas from the coal used, or to employ coal of an inferior
quality, whilst the illuminating power of the coal gas obtained will be increased
by such admixture. And in order to obtain the best results from the combination
of the two gases I prefer to mix them at a point between where the coal

page_text: gas passes from the ordinary condensing apparatus to the purifiers. The
proportion of one gas to the other will depend on the extent of distillation
of the coal or the amount of illuminating power desired to be obtained,
but as a general rule it will bé found that the addition of 1 to 2 per cent.
of the hydrocarbon gas thus obtained mixed with the coal gas will increase
the illuminating power of the gas by one candle in every five feet of gas
consumed.
Having thus described my improvements and means which I adopt in carrying
the same into effect, I would have it understood that I do not confine myself
to the precise details referred to, as these may be varied without departing from
the peculiar character of the Invention, but what I claim is, the treatment of
liquid hydrocarbons for the purpose of obtaining a permanent gas in manner
substantially as explained.
In witness whereof, I, the said Alexander Angus Croll, have hereunto
set my hand and seal, this Twenty-eighth day of August, in the year of
our Lord One thousand eight hundred and sixty-seven.
A. ANGUS CROLL. (L.S.)