IMPROVEMENTS IN FIRE EXTINGUISHERS
Year: 1885

page_text: I EDWIN POWLEY ALEXANDER of 36 Southampton Buildings in the County of
Middlesex, Fellow of the Institute of Patent Agents do hereby declare the nature
of the said invention for "IMPROVEMENTS IN FIRE EXTINGUISHERS" (Comm² to
me from abroad by George Alfred Lindgren of the City and County of La Porte,
State of Indiana, United States of America) 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 Fire Extinguishers of that class wherein the Fire
Extinguishing liquid is retained within a closed vessel and is delivered in a stream
therefrom under pressure onto the fire.
Water alone has been used as the extinguishing liquid or in lieu thereof water
containing in solution various chemicals, which practice has shewn to be effective
in subduing the flames. The propelling agent is ordinarily carbonic acid gas
developed within the vessel under high tension at the time it is to be employed,
said gas escaping with the liquid when the vent-cock is properly turned. Again it
has been proposed to use compressed air in forcing out the liquid, the air being
pumped into the vessel and retained therein until the apparatus is brought into
use. Although carbonic acid gas is a powerful extinguisher the manner of its
delivery from the vessel causes the greater part of such gas to escape into the
atmosphere before reaching the flames. Moreover the pressure of the gas from
within the vessel rapidly diminishes as the discharge proceeds so that the later
portion of the liquid charge fails oftentimes of delivery into the fire. The latter
objection is encountered when compressed air is employed as the impelling medium
for the stream of extinguishing liquid; besides which so far as the air reaches the
fire at all in conjunction with the liquid it aids rather than hinders combustion.
Now this invention is designed to obviate these difficulties and consists in
providing fire-extinguishing vessels of the class named with a charge of Ammonium
gas, said gas being either liquefied or retained in solution under pressure therein
and being used either alone or in conjunction with a charge of water or of chemical
salts contained in solution within the vessel.

page_text: In the accompanying drawing which exhibits one form of apparatus to be used
in the practice of this invention A. denotes the storing vessel of convenient portable
size and made preferably from stout metal or glass sufficiently strong to withstand
a pressure of say 100 lbs. to the square inch. There are the usual straps a and a
handle a¹ attached to the vessel to aid in its easy manipulation. Through the
threaded neck a² on the vessel extends the siphon-tube B which terminates within
near the vessel bottom and at its opposite end has attached thereto a flexible
hose 6 fitted with the ordinary nozzle 6-A stop cock 6' controls the communi-
cation through the tube B to and from the interior of the vessel.
In ordinary practice having filled the vessel about as indicated in the drawing
with water containing a solution of the Chlorides of Sodium and Ammonium in
proportion respectively of 4-7th ounces of the former and 8-7th ounces of the latter
to 1 gallon of water, the vessel is in readiness to receive the charge of Ammonium
gas. It may be noted that the presence of the salts named, or others of like nature
whilst not inimical chemically to the Ammonium gas contribute to the effectiveness
of the solution as an extinguisher and act moreover to maintain the solution in
liquid condition during the severe exposure of winter weather. This latter
safeguard is important since otherwise the apparatus might be rendered useless at
a time when most needed for service. If desired the interior of the vessel when of
metal may be coated enamelled or lined to guard against corrosion and like
precaution may be taken with respect to the siphon-tube, stop-cock and attach-
ments so far as the same are exposed to the action of the charge. The hose b
being detached from the end of the tube B and said tube being tightly fitted to
position in the neck a³ it is merely necessary to connect said tube B by a
convenient conduit or pipe with the source of supply from whence the Ammonium
gas is derived; such gas may be developed in any convenient and well known
manner, as for example by heating together a mixture of Ammonic Chloride and
Caustic Lime as usually practiced.
The Ammonium gas may be allowed to come freely and directly by the conduit
from the retort or like appliance wherein it is generated or else a force-pump may
be interposed or connected up with the conduit so as to exhaust from the retort
and compress the gas into the receiver or vessel. A gauge may be attached to the
conduit or at other convenient point to regulate the supply and pressure of the gas
to the receiver. On entering the vessel the gas is greedily absorbed by the liquid
and so continues until the point of saturation is reached when the liquid will
contain many times its volume of this powerful extinguishing gas. The supply is
continued thereafter until a pressure of some 40 or 50 pounds to the square inch is
obtained which when found to remain constant completes the charging of the
vessel The stop-cock b³ is closed the hose b in lieu of the pipe or conduit is
attached to the tube B and the apparatus is now in readiness for use. Obviously
by providing a sufficient supply of the Ammonium gas and having several branch
conduits delivering to as many vessels it is practicable to cheaply and rapidly
charge all of these at a single setting of the appliances. Instead of having a
volume of water within the vessel A the Sodic and Ammonic Chlorides may be
dropped therein as dry salts if desired and the Ammonium gas be forced into the
receiver under such conditions of pressure and temperature as will effect its direct
liquefaction. This produces in concentrated form a most powerful extinguisher
capable of cooling and quenching an immense surface of burning material when
projected thereon,
Quite aside however from the extinguishing qualities of the Ammonium gas it is
to be noted that either in solution or in liquefied condition, as the case may be,
it is thus bodily retained in large measure until it reaches the flame, so far
distinguishing itself in practical function from the carbonic acid gas heretofore
employed,
Moreover when the stop cock is turned to release the charge the consequent
diminution in pressure causes a portion of the Ammonium gas which had been
liquefied or super-charged to pass at once into gaseous form within the vessel, só

page_text: that with each descent of 1 lb. in internal pressure upon the receiver there is being
constantly developed therein fresh volumes of gas to act elastically as the impelling
medium-By this peculiar quality of the Ammonium gas, the requisite force of
projection is more constantly maintained until the vessel is emptied than in any of
the types heretofore adopted.
Manifestly this invention is not restricted in benefit to any one form, size, special
construction or material for the receiving vessel; nor to any one particular mode of
generating or storing the Ammonium gas therein.
Having now particularly described and ascertained the nature of the said and in
what manner the same is to be performed, I declare that what I claim is
1. A fire extinguisher consisting of the usual strong vessel or receiver having
controllable outlet and containing a charge of Ammonium gas therein under
pressure, substantially as described.
2. A fire extinguisher consisting of the usual strong vessel or receiver having
controllable outlet and containing a charge of Ammonium gas in liquefied or
anti-freezing solution therein said gas serving as the impelling motor to deliver the
charge onto the fire substantially as described.
EDWIN P. ALEXANDER,
Fel, Inst. P.A.