Improvements in and relating to a Process and Apparatus for Automatically Extinguishing Fires.
Year: 1893

page_text: Date of Application, 13th Feb., 1893
Complete Specification Left, 13th Dec., 1893-Accepted, 13th Jan., 1894
PROVISIONAL SPECIFICATION.
Improvements in and relating to a Process and Apparatus for
Automatically Extinguishing Fires.
I, JAMES LONGSHAW of 3 Church Street Seaforth, in the County of Lancaster,
Technical Chemist, do hereby declare the nature of this invention to be as
follows:-
This invention relates to a process and apparatus for automatically extinguishing
fires and consists in providing means whereby, upon a certain predetermined tem-
perature being reached, the air surrounding and adjacent to the fire is displaced
automatically by a gas which is incapable of supporting combustion.
also provided for signalling the locality of the fire.
Means are
In carrying this invention into effect suitable pipes are arranged at convenient.
spots within or about the room or space which it is desired to protect from fire.
These pipes contain liquefied carbonic acid gas and are preferably in communication
with mains or reservoirs also charged with the liquefied gas. The ends of the pipes
are closed by fusible plugs formed of any usual metallic alloy and contained within
a casing made of wood or other material incapable of readily transmitting heat.
In connection with the fusible plug is a second plug with an enlarged head
constructed of copper or other metal having high heat conductivity. Any heat
generated in the vicinity is thus immediately absorbed and conveyed to the fusible
plug, which when the predetermined temperature has been reached, melts, and
allows the carbonic acid gas to escape.
For indicating at the fire station or other place the locality of the fire, I combine
with each pipe or series of pipes a U-shaped piece of tube one branch of which is
in connection with the pipes, the other branch being stopped. The bend of the
tube is filled with mercury which at normal pressures would be at an equal height
in both limbs of the tube. Contained within the branch of the tube which is in
communication with the extinguishing pipe and insulated therefrom is an electrical
contact which is normally in contact with the mercury, thus completing an electric
circuit to ring a bell and operate an indicating device of the usual sort. When the
pipes are charged with the carbonic acid gas the pressure displaces the mercury
into closed limbs of the tube, and the circuit is broken only to be re-made when the
pressure diminishes owing to the escape of the gas allowing the mercury to resume
its original position in the bend of the tube.
Dated this 11th day of February A.D. 1893.
WILLIAM E. HEYS,
Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in and relating to a Process and Apparatus for
Automatically Extinguishing Fires.
I, JAMES LONGSHAW, of 3 Church Street, Seaforth, in the County of Lancaster,
Technical Chemist, 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 :- +
This invention relates to a process and apparatus for automatically extinguishing
Pri

page_text: fires and consists in providing means whereby, upon a certain predetermined tem-
perature being reached, the air surrounding and adjacent to the fire is displaced
automatically wholly or in part by a gas which is incapable of supporting com-
bustion. Means are also provided for signalling the locality of the fire.
In carrying this invention into effect suitable pipes are arranged at convenient
spots within or about the room or space it is desired to protect from fire. These
pipes contain or communicate with a store of compressed or liquidified carbonic acid
gas. The ends of the pipes or of branches therefrom are closed by fusible plugs
formed of any usual fusible alloy contained within a casing constructel of a suitable
non-conductor of heat such as wood. In connection with the fusible plug there is
a disc formed of copper or other metal having a high conductivity. An increase of
temperature in the vicinity is thus quickly communicated by the disc to the fusible
plug, which when the predetermined temperature has been reached, melts and
allows the carbonic acid gas to escape.
For indicating at fire stations or other places, the locality of the fire, I may
combine with each pipe or series of pipes a U-shaped tube, one branch of which is
in communication with the pipes, the other branch being stopped or sealed. The
bend of the tube is filled with mercury which at the normal atmospheric pressure
would stand at an equal height in the two limbs of the tube. In that limb of the
tube which is in communication with the carbonic acid containing pipes there is an
electrical contact insulated from the tube and normally making contact with the
mercury thus completing a circuit through a fixed electrical connection with the
pipe or tube and actuating an electric bell or other signalling device. When
the pipes are charged with the liquid carbonic acid gas, its pressure displaces the
mercury in the limb of the U-tube within which it is contained, and the electric
circuit is opened. So soon however as the apparatus comes into action and the
carbonic acid gas is liberated from its pipes, the pressure is reduced, the mercury
resumes its normal position, and the electric circuit is again closed, actuating the
signal.
I will more particularly describe my said invention with reference to the
accompanying drawings in which--
Figure 1 is an elevation of the apparatus including only one of the fusible plugs.
Figure 2 is a sectional elevation of a fusible plug, and
Figure 3 is a vertical section through the U-tube.
A A are the pipes through and by means of which the carbonic acid gas is
distributed to the fusible plugs, of which only one is shewn at B. CC are
cylinders or metallic reservoirs charged with the liquidified carbonic acid gas and
having outlets D D connected with the pipes A, controlled by the valves E E;
as many being provided as requisite. F is a valve in the pipes A for the purpose
of isolating the service from the cylinders C, when required for repairs and the
like purposes. As many such valves are included in the pipes as may be required.
G is a manometer for indicating the pressure in the service pipes. H is the U-pipe
shewn separately in vertical section in Figure 3.
As already described this tube is charged with mercury which at normal
atmospheric pressures will stand at about an equal height in each limb. One of
the limbs is closed and the other communicates through the branch A' with
the pipes containing the carbonic acid gas. In this limb there is arranged a
metallic contact such as the adjustable rod T which is insulated from the tube and
is in contact with the mercury when the pressure in each limb is about the same.
This contact T is included in an electric circuit which is completed by the mercury,
the metal of the tube and a terminal such as T¹ or other contact. When the
apparatus is in open communication with the pipes A, the pressure therein forces
down the mercury in the limb h and forces it out of contact with T, thus opening
the circuit. When owing to the occurrence of a fire, the apparatus comes into
action, the carbonic acid gas is liberated and the pressure is released. Conse
quently, the level of the mercury is restored and the electric circuit is closed,
ringing a bell or actuating an electric signal at the fire station or elsewhere.

page_text: The construction of the fusible plug which I prefer to use is illustrated by
Figure 2. In this construction J is a copper plug embedded in the block K of
fusible metal and provided with a disc shaped head L of copper or other high
conductivity metal. The block forming the actual fusible plug is secured in a
casing M formed of wood ebonite celluloid or other suitable non-conductor of heat
which in turn secured in the outer casing N, screwed upon the branch O of the
pipe A. Upon the occurrence of a fire in the neighbourhood of one of the plugs,
the large surface L rapidly conducts the heat through J to the fusible alloy, upon
the melting of which the passage to the tube A becomes open and the imprisoned
gas escapes rapidly, mixing with and displacing the air and thus extinguishing the
fire without further damage than that created by the flames heat and smoke.
As many of the cylinders or reservoirs of the liquefied carbonic acid gas may be
used as may be necessary or desirable and they may be located together or at
different points of the system.
The pipes A. A need not be of large diameter, half an inch being sufficient for
most purposes, especially when the stores of carbonic acid gas in the reservoirs are
distributed at different points in the protected area.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is :-
:-
1. Apparatus for automatically extinguishing fires by means of carbonic acid
gas, constructed arranged and operating substantially as hereinbefore described and
as illustrated by the accompanying drawings.
2. In apparatus for automatically extinguishing fires, a fusible plug consisting
of a metal disc of good heat conductivity, a plug of similar metal connected there-
with, a block or plug of fusible alloy in which the last named plug is embedded, a
heat insulating material surrounding the fusible alloy, and an external casing by
which the plug may be secured to the service pipes, constructed substantially as
hereinbefore described and as illustrated by the accompanying drawings.
3. In apparatus for automatically extinguishing fires, an electrical signalling.
device consisting of a U-shaped tube one end of which is closed and the other end
of which communicates with the extinguishing fluid under pressure, mercury
contained with the U-tubes, an insulated electric contact in one limb of the tube,
and a second electric contact with the mercury, constructed arranged and operated
substantially as herein before described.
4. In apparatus for automatically extinguishing fires, the combination and
arrangement with a service of pipes fitted with fusible plugs, of cylinders or
metallic reservoirs charged with compressed or liquefied carbonic acid gas, sub-
stantially as hereinbefore described and as illustrated by the accompanying
drawings.
Dated this 12th day of December A.D. 1893,
WILLIAM E. HEYS,
Agent for the Applicant.