Improvements in the Manufacture of Gas from Mineral Oils, and in the Apparatus Employed therefor.
Year: 1894

page_text: Date of Application, 23rd Jan., 1894
Complete Specification Left, 22nd Oct., 1894-Accepted, 24th Nov., 1894
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Gas from Mineral Oils, and in
the Apparatus Employed therefor.
We JOHN GALLETLY of 13 Murieston Crescent, Edinburgh, County of
Midlothian, North Britain, Chemist, and HARRY ARMOUR of 54 Holly Bank
Terrace Edinburgh County of Midlothian, North Britain, Chemical Engineer, do
hereby declare the nature of the said invention to be for,-IMPROVEMENTS IN
THE MANUFACTURE OF GAS FROM MINERAL OILS AND IN THE APPARATUS
EMPLOYED THEREFOR, and to be as follows:-
The invention has for its object the manufacture of gas from mineral oils
including petroleum, or liquids generally known as hydrocarbons, in improved
apparatus by which the operation is carried on in a nearly continuous manner, so
that large quantities of gas may be made with comparatively few retorts and with
economy both in labour and plant. The chief difficulty in making oil gas at
present arises from the constant deposition of carbon on the inside of the retort
requiring regular interruptions of the process for its removal. The carbon besides
is a bad conductor of heat and this necessitates a high temperature on the retort
leading to its rapid destruction.
In carrying out our invention we employ, by preference, a horizontal retort,
circular in section which is kept slowly turning. A hollow shaft, which also
revolves passes through the retort projecting at both ends. A scraper in the form
of a spiral screw, loosely fitting the shaft and turning with it, passes from end to
end of the retort or nearly so. This spiral scraper, which is preferably made in
sections, rests chiefly against the inside face of the retort scraping off carbon which
deposits during the working operation and removing it to one end of the retort.
The oil is led into the hollow shaft by a small pipe in a regulated stream near to
one end and at a short distance within the retort and it gets heated and partly
vapourised as it flows towards the other end, near which it escapes through suitable
openings into the body of the retort, where it gets converted into gas in passing
back along its red hot sides. The gas thus formed leaves the retort by passing
through slits or holes into the shaft, near the opposite end from that at which the
oil vapour enters, and is conducted by a suitable arrangement from the end of the
shaft to the gas mains or condensers. A plug is placed in the shaft behind
the holes by which the gas enters it to prevent the current of gas from interfering
with the regular flow of oil vapour from the holes near the other end. The pipe
conveying the oil may pass through a turned hole in the centre of this plug, or it
may be introduced at the other end of the shaft. This pipe can also serve to
convey steam, or water for conversion into steam, into the retort.
The carbon removed from the sides by the scraper accumulates at one end of the
retort and requires to be removed at intervals. To do this with safety we displace
the gas in the retort with steam. This may be done by shutting off the run of oil
and, as indicated, turning on a stream of water or steam through the oil pipe.
When the retort is filled with steam the revolution of it is stopped and the
connexion to the gas main shut off. By opening or removing a small door on the
end of the retort the carbon may then be removed.
The object of the invention would be secured by having the retort stationary
whilst the screw revolved; or, reversely, the screw stationary with the retort
revolving. And a horizontal position is not essential for the retort but we prefer

page_text: a revolving retort in a horizontal position to any other as being least likely to get
out of shape.
Dated this Twenty-second day of January 1894.
JOHN GALLETLY.
HARRY ARMOUR.
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Gas from Mineral Oils, and in
the Apparatus Employed therefor.
We JOHN GALLETLY of Thirteen Murieston Crescent Edinburgh County of
Midlothian North Britain, Chemist, and HARRY ARMOUR of Fifty-four Holly
Bank Terrace, Edinburgh, County of Midlothian, North Britain, Chemical
Engineer do hereby declare the nature of this invention and in what manner
the same is to be performed, to be particularly described and ascertained in and
by the following statement :-
The invention has for its object the manufacture of gas from mineral oils,
including petroleum, or liquids generally known as hydrocarbons in improved
apparatus by which the operation is carried on in a nearly continuous manner, so
that large quantities of gas may be made with comparatively few retorts and with
economy both in labour and in plant.
In describing our invention and the method of carrying it out reference is made
to the sheet of drawings hereunto appended illustrating the arrangement which by
preference we employ. In these the same letters are used where repeated to mark
the same or like parts of the apparatus.
Fig. 1 is a longitudinal vertical section of the apparatus.
Figs. 2 and 3 are vertical sections of scrapers at right angles to the view in
Fig. 1.
Fig. 4 is a plan showing position of scrapers in contact with retort.
A horizontal cylindrical metal retort A Fig. 1 is used which is slowly turned.
It revolves round the shaft B. The shaft B, which also revolves, passes through
the retort resting on the plumber blocks C. Both retort and shaft require to be
turned slowly, and this may be done by the use of the ratchet wheel W 1 fixed on
the end of the retort and a similar wheel W 2 fixed on the shaft. A frame moving
horizontally backward and forward arranged above these wheels will turn the
retort while moving in one direction and the shaft while moving in the opposite
direction. Tooth and pinion gearing may be used instead of ratchet wheels. The
portion of the shatt inside the retort is square and the rest circular. In order to
remove the crusts of carbon deposited on the inner surface of the retort scrapers F
are arranged along the square portion of the shaft which are turned round by it
and serve the purpose of a spiral screw. These besides scraping off the carbon or
coke as it is formed push it along to one end of the retort. They are preferably
made of cast iron or steel of the form shown on the drawings. They may have
two arms with scraping plates as in Fig. 2 C or only one arm and scraping plate as
shown in Fig. 3. The whole length with two arms is shorter than the diameter of
the retort. The central opening is oblong and just larger than the side of the shaft
in one direction but considerably more in the other so that as it is turned round it
slides across the shaft to allow each scraping plate to meet the surface of the
retort at each revolution. The plate C is bevelled back from the surface that
touches the retort at an acute angie to form a sharp scraping edge and is rounded
on the face to the curve of the retort. These scraping pieces may be placed on
the shaft with the arms alternately at right angles to each other or in one line.
The scraping plates when the arms are in one line are long enough to overlap each
other and are set at an angle to the shaft as seen in Fig. 4. This causes the solid
pieces of carbon to collect at one end of the retort. The crust of carbon as usually

page_text: deposited is soft and brittle, the weight of the scraper being sufficient to remove it.
N1 N2 are doors by which the carbon is drawn from the retort and allow of the
introduction of tools to loosen and clean out any crusts that may adhere to the
scrapers.
The oil is introduced in a regulated stream by the pipe H into the shaft B where
it gets heated and partly vapourised and passes into the body of the retort by the
openings I. There it gets converted into permanent gas. This passes out of the
retort by the openings J into the shaft, thence by the valve K into the gas main L.
A plug P is inserted into the shaft dividing it into two portions one for the
introduction of the oil and the other for leading the gas away from the retort.
The branch pipe S on the oil pipe supplies steam for use in the manner hereafter
referred to.
In working the apparatus the retort is heated as uniformly as possible to the
temperature required, a low heat giving a richer gas but less in volume than a
higher heat. The uniformity of the heat is obtained by keeping the retort well
above the furnace bars and by its revolution. After a certain quantity of oil has
been used and the corresponding quantity of gas obtained the revolutions of the
shaft and retort are stopped, the current of oil shut off, and the steam turned on
gently to sweep the gas out of the retort. The valve K on the main L is then
closed when one or both doors N1 N2 are opened and the carbon raked out..
When it is seen that the apparatus is clean and the openings in the shaft clear the
doors are again closed and the operation recommenced. The quantity of carbon
deposited depends much on the kind of oil used and its condition as regards
purification and therefore the intervals between the periods for cleaning must be
ascertained from practical working.
The object of the invention would he secured by having the shaft stationary
while the retort revolved and, in a much less satisfactory manner, by having the
retort stationary with the shaft revolving. And a horizontal position is not.
essential for the retort but we prefer a retort revolving in a horizontal position, or
nearly so, to any other as being least likely to get out of shape.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
1. The employment of scrapers loosely fitting the shaft so as to allow for
expansion and of their adjustment to the inside face of the retort.
2. The arrangement of apparatus by which the carbon deposited in the retort is
removed and carried to one end of it during the manufacture of the gas substantially
as described.
3. The general arrangement of apparatus whereby the manufacture of oil gas is.
conducted in a practically continuous manner substantially as described.
Dated this 20th day of October 1894.
JOHN GALLETLY.
HARRY ARMOUR.