AN IMPROVED METHOD OF AND MEANS OR APPARATUS FOR PREVENTING EXPLOSIONS IN MINES
Year: 1881

page_text: LETTERS PATENT to Charles Denton Abel, of No. 28, Southampton
Buildings, Chancery Lane, in the County of Middlesex, for an Invention
of "AN IMPROVED METHOD OF AND MEANS OR APPARATUS FOR PREVENTING
EXPLOSIONS IN MINES." A communication from abroad by Oscar Bustin, of
PROVISIONAL SPECIFICATION left by the said Charles Denton Abel at the
Office of the Commissioners of Patents on the 22nd April 1881.
CHARLES DENTON ABEL, of No. 28, Southampton Buildings, Chancery Lane, in
the County of Middlesex. "AN IMPROVED METHOD OF AND MEANS OR APPARATUS
FOR PREVENTING EXPLOSIONS IN MINES." [A communication from abroad by
Oscar Bustin, of Liège, in the Kingdom of Belgium.]
According to this Invention the explosion of the carburetted hydrogen gases or
fire damp in mines is prevented by mixing therewith a quantity of carbonic acid
gas sufficient to neutralize the explosive nature of such gas, but insufficient to
inconvenience the miners, it having been found that a comparatively small quantity
of carbonic acid gas mixed with fire damp destroys its explosive nature.
For this purpose the carbonic acid gas may be produced in the mine itself in
apparatus similar to those well known as "extincteurs," or those used in the
manufacture of aerated waters. But in order to determine with sufficient accuracy
the quantities to be injected to fulfil the above mentioned conditions, it is preferred
to produce the carbonic acid gas at the surface of the ground, and to store it under
a pressure of several atmospheres in a reservoir of some capacity, from which pipes
lead to the different workings of the mine, so as to enable the gas to be directly
injected into the surrounding atmosphere at any point where this may assume an
explosive nature.
The arrangements and apparatus for carrying out the said Invention may be
variously modified; thus according to the plan employed, by preference, there is
established at or near the pit's mouth apparatus of any suitable known construction
for the production of carbonic acid gas, such as a vessel charged with sulphuric

page_text: acid communicating with a second" vessel charged with bicarbonate of soda and
provided with stirring apparatus, into which vessel the acid is allowed to flow, the
carbonic acid gas generated being collected in a gas holder, from which it is
conveyed by a force pump down a main pipe leading down the shaft of the mine,
and provided with branches having cocks or valves at the level of each working.
To these branches are temporarily connected strong receptacles of moderate
dimensions, into which the carbonic acid is charged at any desired pressure by
means of the before mentioned pump. When the desired pressure (indicated by a
pressure gauge) is attained, the cock on the vessel is closed, and the vessel is
detached and conveyed to any part of the workings where blasting operations are
being carried on. At such point the vessel is attached to a short length of pipe
serving to convey the gas to the immediate vicinity of the blasting operation, and
when the charge is about to be fired, the cock of the vessel is opened so as to allow
its gaseous contents to mingle with the atmosphere of the workings at that point,
whereby, when the firing has been effected, there will be sufficient carbonic acid.gas
present to prevent any explosion of fire damp. The vessels are by preference of such
a capacity that their gaseous charge when expanded amounts to about one seventh
part of the volume of air in the part of the working into which it is discharged,
assuming this to be at an average depth below ground. A number of the said
vessels may be charged successively from the main pipe, as described, and trans-
ported on a truck to be distributed at various points of the workings. Where the
current of air in the working is considerable, temporary means may be employed,
such as moveable screens for intercepting the current and preventing the carbonic
acid. gas from being dispersed too rapidly on issuing from the vessels while the
blasting operation is being carried on.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Charles Denton Abel in the Great Seal Patent Office on the
21st October 1881.
CHARLES DENTON ABEL, of No. 28, Southampton Buildings, Chancery 'Lane, in
the County of Middlesex. "AN IMPROVED METHOD OF AND MEANS AND APPARATUS
FOR PREVENTING EXPLOSIONS IN MINES." A communication from abroad by
Oscar Bustin, of Liège, in the Kingdom of Belgium.
According to this Invention the explosion of the carburetted hydrogen gases or
fire-damp in mines is prevented by mixing therewith a quantity of carbonic acid
gas sufficient to neutralize the explosive nature of such gas, but insufficient to
inconvenience the miners, it having been found that a comparatively small quantity
of carbonic acid gas mixed with fire-damp destroys its explosive nature.
.For this purpose the carbonic acid gas may be produced in the mine itself in
apparatus similar to those well known as "extincteurs," or those used in the
manufacture of aërated waters. But in order to determine with sufficient accuracy
the quantities to be injected to fulfil the above mentioned conditions, it is preferred
to produce the carbonic acid gas at the surface of the ground, and to store it under
a pressure of several atmospheres in a reservoir of some capacity, from which
pipes lead to the different workings of the mine, so as to enable the gas to be
directly injected into the surrounding atmosphere at any point where this may
assume an explosive nature.
The arrangement and apparatus for carrying out the said Invention may be
variously modified; thus according to the plan employed, by preference, there is
established at or near the pit's mouth apparatus of any suitable known construction
for the production of carbonic acid gas, such a vessel charged with sulphuric acid
communicating with a second vessel charged with bicarbonate of soda and provided
with stirring apparatus, into which vessel the acid is allowed to flow, the carbonic
acid gas generated being collected in a gas holder, from which it is conveyed by a
force pump down a main pipe leading down the shaft of the mine, and provided
with branches having cocks or valves at the level of each working. To these
branches are temporarily connected strong receptacles of moderate dimensions,
into which-the carbonic acid is charged at any desired pressure by means of the
before mentioned pump. When the desired pressure (indicated by a pressure
gauge) is attained, the cock on the vessel is closed, and the vessel is detached and
conveyed to any part of the workings where blasting operations are being carried
on.
At such point the vessel is attached to a short length of pipe serving to
convey the gas to the immediate vicinity of the blasting operation, and when the
charge is about to be fired, the cock of the vessel is opened so as to allow its
gaseous contents to mingle with the atmosphere of the workings at that point,
whereby, when the firing has been effected, there will be sufficient carbonic acid
gas present to prevent any explosion of fire-damp. The vessels are by preference
of such a capacity that their gaseous charge when expanded amounts to about one.
seventh part of the volume of air in the part of the working into which it is
discharged, assuming this to be at an average depth below ground. A number
of the said vessels may be charged successively from the main pipe, as described,
and transported on a truck to be distributed at various points of the workings.
Where the current of air in the working is considerable, temporary means may be
employed, such as moveable screens for intercepting the current and preventing
the carbonic acid gas from being dispersed too rapidly on issuing from the vessels
while the blasting operation is being carried on.
The accompanying Drawings shew how this Invention may be applied in a mine,
Fig. 1 being a vertical section shewing the upper ground and two of the galleries

page_text: or workings. at any depths below; Fig. 2, a plan on the line A, B, of Fig. 1; and
Fig. 3, a part transverse section on C, D, shewing the workings following the
supposed direction of the stratum operated on. A is a vessel from which sulphuric
acid is supplied in regulated quantity to the receptacle B charged with bicarbonate
of soda, and provided with an agitator. The carbonic acid gas generated in B is
collected in the gasometer C, and from this it is drawn by a pump D worked by
hand or other convenient motor and compressed, being delivered by a pipe E
descending the shaft to receptacles R situated in the several galleries G.. These
receptacles are connected to the pipe E by unions interposed between two stop
cocks, r. When a receptacle is charged these cocks are closed, the union is
disconnected, and the charged receptacle R is carried or conveyed on a truck to
the neighbourhood of the place P, where a blast is to be fired, or where there is
danger of explosion of fire-damp. A sufficient length of pipe being then connected
by the union to the receptacle R, the cock r¹ is opened, and the carbonic acid gas
issuing from the receptacle neutralises the combustible character of the atmosphere
at and about the place P. The blast can then be fired, and as the workmen do
not return to the spot till after the smoke is mostly cleared away by the ventilation,
there is no danger of their suffering from the presence of the carbonic acid gas, which
will have passed away along with the smoke. In cases where a rapid ventilating
current might draw off the carbonic acid gas without allowing it to mix with the
explosive atmosphere, it is advisable to obstruct the current for a time until the
proper mixture is secured.
Although the production of the carbonic acid has been described as being
effected by the action of sulphuric acid on bicarbonate of soda, this being a
rapid and easy method of producing the gas, other known methods may obviously
be adopted.
Having thus described the nature of the said Invention and in what manner
the same is to be performed, as communicated to me by my foreign correspondent,
I claim,―
First. The herein described method of preventing explosions in mines by mixing
with the explosive atmosphere a quantity of carbonic acid gas delivered froin
portable receptacles in which the gas is stored under pressure.
Second. For preventing explosions in mines, the use of apparatus consisting of
a generator and gasometer. or holder of carbonic acid gas, a compressing pump,
and portable receptacles for the compressed gas, with the necessary connecting
pipes, stop cocks, and unions, arranged and operating substantially as herein
described.
In witness whereof, I, the said Charles Denton Abel, have hereunto set my
hand and seal; this Twentyfirst day of October, in the year of our Lord