IMPROVED MEANS OF AND APPARATUS FOR INCREASING THE ILLUMINATING POWER OF COAL GAS
Year: 1880

page_text: LETTERS PATENT to John Macdonald, of No. 171, Queen Victoria Street, in the
City of London, for an Invention of "IMPROVED MEANS OF AND APPARATUS
FOR INCREASING THE ILLUMINATING POWER OF COAL GAS."
PROVISIONAL SPECIFICATION left by the said John Macdonald at the
Office of the Commissioners of Patents on the 14th December 1880.
JOHN MACDONALD, of No. 171, Queen Victoria Street, in the City of London.
"IMPROVED MEANS OF AND APPARATUS FOR INCREASING THE ILLUMINATING
POWER OF COAL GAS."
The object of this Invention is the enrichment of coal gas by passing it through
or over a carburetting material (such as gasoline, for example) in such a manner as
to allow only a small portion of such carburetting material to be exposed to the
action of the gas at one time, thus preserving its uniformity of enrichment
throughout, which cannot be done where the gas is brought into contact with the
whole body of the spirit at once; also a means whereby such enriched gas is
rendered permanent. In order to effect the above I construct an apparatus
substantially as follows:-I employ a closed chamber having an inlet and outlet
pipe, and containing one or more tubes tapered towards the bottom; these tubes
extend to about one eighth of an inch of the bottom of the aforesaid chamber, the
outlet at bottom of the tubes being very small, and having suitable valves to close
them automatically during charging. Around the tubes I place sponge or other
suitable absorbent material, in such a manner that the latter is continually kept
saturated with the carburetting material hereafter described. Around the aforesaid
chamber I fix a water tight jacket, in such a manner as when filled with water or
other suitable liquid it prevents any leakage of the carburetting material.
Having first charged the tubes in the aforesaid chamber with the carburetting
material I close them, which causes the valves at the bottom to open and allow a
sufficient portion of the carburetting material to pass into bottom of the chamber
and saturate the sponges therein; I then allow the gas to pass through the inlet
pipe, and make its way through and between the sponges, and thus allow it to
Poxine G21

page_text: absorb a sufficient and uniform quantity of carburetting material to enrich it, and
thus increase its illuminating power.
In order to render coal gas (saturated with the vapor of the carburetting material)
permanent I subject such saturated gas to a heat sufficient to convert it into a
permanent gas. For this purpose I cause the said saturated gas to pass through
a chamber or series of pipes in the form of a coil (by preference). This chamber or
series of pipes or coil I surround with a casing of metal or other suitable material.
Where sheet iron is employed this casing should be jacketted, so that the space
within the jacket may be filled with a material; being a non conductor of heat I
then fill in and around the series of pipes or coil asbestos or other suitable non
combustible material, and beneath I fix a Bunsen or other suitable gas burner in
such a manner that the flame from the burner when lighted may permeate the
non combustible material, so as to heat the chamber, series of pipes, or coil, and
keep same at a constant heat, sufficient to decompose the vapor of the carburetting
material. The coal gas is thus permanently enriched, so that no condensation takes
place from any change of temperature in the pipes, which is unadvoidable when
simply a mechanical mixture of the coal gas and the vapor of the carburetting
material is made by the ordinary method of carburetting.
Instead of heating the chamber, pipes, or coil, as above, they may be otherwise
suitably heated. Where gas of a very rich quality is required, I in the first place
heat the coal gas by causing it to pass through a chamber, coil, or series of pipes
(similar to that described for decomposing the saturated gas) before entering the
carbureter; it by this means absorbs a much larger quantity of the carburetting
material, which is then passed through the decomposing coil, the result being a gas
of much richer quality than that before described.
When the before named apparatus is not employed to decompose the vapor of
the carburetting material, in this case in order to prevent condensation in the pipes
I connect to the outlet of the aforesaid chamber another chamber, containing an
absorbent material, cuttings of Turkey sponge for example, which may be renewed
from time to time. When sponge is employed I place it in such a way as to prevent
contact with any metal that may be used. I may employ one or more of these
absorbing chambers as found desirable, according to the distance the carburetted
gas has to travel.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Macdonald in the Great Seal Patent Office on the 14th June
1881.
JOHN MACDONALD, of No. 171, Queen Victoria Street, in the City of London.
"IMPROVED MEANS OF AND APPARATUS FOR INCREASING THE ILLUMINATING
POWER OF COAL GAS."
The object of this Invention is the enrichment of coal gas by passing it through
or over a carburetting material (such as gasoline, for example), in such a manner as
to allow only a small portion of such carburetting material to be exposed to the
action of the gas at one time, thus preserving its uniformity of enrichment
throughout, which cannot be done where the gas is brought into contact with the
whole body of spirit at once; also a means for preventing condensation in the pipes
of such enriched or carburetted gas, as is the case with gas carburetted in the
ordinary way. And in order that my said Invention may be better understood,
reference is had to the illustrative Sheet of Drawings accompanying this Specifi-
cation, in which is represented at A, Figure 1, a section of a carburetter ;
B, Figure 1, section of an apparatus for rendering carburetted gas permanent.
Figure 2 shews elevation of carburetter and retort connected, and as they would
appear when in use.
Figure 3 shews section of modified form of carburetter connected to two retorts
for the purpose hereinafter described.
Figure 4 shews another form of carburetter partly in section, and especially
adapted for countries where only a certain quantity of spirit is allowed to be kept
in a vessel at one time.
Figure 5 is a cross section of same.
Figures 6 and 7 shew detached views of part of a carburetter hereafter
described.
At A, Figure 1, is shewn a carburetter; b shews inlet for gas from meter;
d, outlet to retort; f shews tank to hold supply of spirit, to which is connected
pipe g; c shews a series of chambers formed by the partitions c¹ extending alter-
nately to within a short distance of the top or bottom of the main chamber
forming the carburetter, and around the aforesaid tank f; e is a funnel for filling
the tank f with spirit; h is a float valve to regulate the supply of spirit auto-
matically to the carburetter. The chambers care to contain sponge or other
absorbent material.
At B, Figure 1, is shewn the retort, in which a is a coil; b, chamber to hold a
material, being a nonconductor of heat; b¹ shews inlet for carburetted gas, and d'
shews outlet for enriched permanent gas.
That part of the retort containing the coil is to be filled with asbestos or other
suitable non combustible material; a' shews a Bunsen burner for heating the
asbestos and coil.
The action is as follows:-The tank f being supplied, the carburetting material
will run out of the pipe g into the carburetter and saturate the sponges or other
absorbent material in the chambers c, and when those are thoroughly saturated the
recess in which the float valve h acts will fill, thus causing the said valve to float
and close the pipe g, and upon the gas being admitted it will pass through the
holes shewn in the inlet b in the direction of the arrow's flight, permeating the
saturated sponges, thus causing the gas to be thoroughly charged with the vapour
of the spirit, and becoming uniformly enriched as long as any spirit remains in the
tank the sponges being kept saturated by the action of the valve h. The

page_text: enriched gas then passes through the holes shewn in the outlet pipe d through the
beated coil a in the retort B, thus changing the vapour from the carburetting
material with which the gas is charged into a permanent gas, and thereby
preventing condensation in the pipes, as is the case when gas is carburetted
in the ordinary way, simply by passing it through or over the carburetting
material. The carburetted gas then passes out of the retort through the pipes
to the burners. When it is desired to enrich the gas to its fullest extent, and
where a large number of burners are to be supplied, I prefer to employ,
according to this Invention, two retorts, as shewn at Figure 3, one marked C
to heat the gas before it enters the carburetter, and the other marked E to convert
the carburetted gas into a permanent gas similar to that described with reference
to B, Figure 1. It will be seen that in this case I have shewn a modified form of
carburetter. D is the carburetter ; F is a main tank to keep the tank in the carburetter
regularly supplied to about the level shewn by the line w, w, by means of the ball
cock G. The carburetter is kept regularly supplied with spirit by means of the pipe o,
valve n, and float m, which act in the same way as the float valve before described
with reference to Figure 1, the valve closing when the spirit is at the level shewn
by the line k. s is a pipe extending above the oil level line w, w, in the tank ƒ so as
to allow the passage of any light gas evolved by the heat. This carburetter may also
be partly filled with sponges or other absorbent material to be kept saturated. The
hot gas from the retort C enters the carburetter D through a series of finely
perforated pipes, as shewn at p, Figures 3, 6, and 7; these pipes are covered with
the carburetting material to a certain depth, and the gas forces its way through the
perforations i, i, in a finely divided state into the carburetting material. The heat
to which the gas should be raised is controlled by the boiling point of the carbu-
retting material employed. (In some cases where heavy oils are employed it will be
found advantageous to heat the carburetter externally; this may be done by
applying a water jacket round the carburetter heated by gas or other suitable
means, or heat may be applied direct to the carburetter by means of a gas jet or
otherwise, so as to accelerate the vapourization of the oil and prevent waste.) The
gas then passes through the saturated sponges in the direction of the arrow's flight
into the second retort E, where the action is the same as that described with reference
to Figure 1.
In
At Figures 4 and 5, the carburetter is shewn constructed to hold a given
quantity of carburetting material in a series of chambers so as to comply with the
regulations of certain places where only a given quantity of light spirit is allowed
to be kept in one place, and no vessel to contain more than a certain quantity.
this case shews a series of tubes to contain, say, one pint of carburetting material
each, the number of tubes being regulated according to the quantity of spirit
allowed to be kept in the carburetter. The tubes are made smaller at bottom, and
are closed when the spirit is at the desired level by means of a ring of cork h (for
example) floating in the spirit and closing the valves of all the tubes at once in the
same way as the pipe is closed with reference to Figure 1. The sponges to be
saturated are fitted in the space marked A¹ of the carburetter, the action being
precisely the same as that described with reference to Figure 1. In some cases,
according to this Invention, instead of employing the aforesaid retort, I cause the
enriched gas to pass through some absorbent material, in order to prevent conden-
sation in the pipes; this I propose to effect by fitting one or more closed vessels
charged with the absorbent material (Turkey sponge, for example) to the pipes
which convey the enriched gas to the burner, so that the said pipes may
communicate with the interior of the said vessel in order that the gas may pass
through the absorbent material, which I occasionally heat by any suitable means so
as to vapourize the spirit contained in the material.
Having thus described and ascertained the nature and object of my said
Invention, and the means of carrying the same into practical effect, I would remark
in conclusion that I do not wish to confine myself to the precise details described

page_text: and shewn, as the same may be varied without departing from the principles of
my said Invention, which I declare to consist in and therefore claim,-
Firstly. Constructing a carburetter with an automatic feed for the supply of
carburetting material thereto, so that only a constant and definite but sufficient
quantity of carburetting material contained therein shall be exposed to the action
of the gas, substantially as and for the purposes set forth.
Secondly. In combination with my improved carburetter of a heating coil or
equivalent means for heating the carburetted gas, substantially as set forth.
Thirdly. Heating the coal gas before being carburetted and causing it to enter the
carburetter hot in combination with the retort for heating the carburetted gas,
substantially as set forth.
Fourthly. Passing carburetted coal gas through an absorbent material, sub-
stantially as and for the purpose set forth.
Fifthly. The general combination and arrangement of parts constituting my
improved automatically supplied carburetting appliance, substantially as described
with reference to the accompanying Drawings.
In witness whereof, I, the said John Macdonald, have hereunto set my
hand and seal, this Tenth day of June, in the year of our Lord One thousand
eight hundred and eighty one.
JNO. MACDONALD. (L.S.)