Improved Safety-device for Naptha-engines.
Year: 1888

page_text: Improved Safety-device for Naptha-engines.
I, HERBERT JOHN ALLISON of 52 Chancery Lane, London, in the County of
Middlesex, Patent Agent, do hereby declare the nature of this invention which has
been communicated to me from abroad by the Gas Engine and Power Company, a
Corporation organised under the laws of the State of New York in the United States
of America and whose principal place of business is in the City of New York, and in
what manner the same is to be performed to be particularly described and ascer-
tained in and by the following statement :-
This invention relates to the employment in connection with a naptha-engine, of a
novel safety-device whereby, in the event of a failure of the naptha-vapor exhausted
from the working cylinder to condense, the engine will automatically cease its move-
ment and the vaporising burners be extinguished so as to prevent the possibility of an
accidental ignition of the naptha or its vapor and a liability to fire therefrom..
It consists in the combination with the pump by which the retort of the engine is
fed with naptha, and with the condenser into which the naptha vapor is discharged
from the exhaust port of the engine, of an air-tight safety-chamber which connects at
the bottom with the supply pipe of the feed-pump and at the top by a very small
connecting pipe with the upper portion of the naptha reservoir, and into which the
discharge pipe from the condenser is made to open, whereby in the event of a discharge
gas or vapor into said chamber from the condenser, the suction of the feed-pump
will be broken and the supply of naptha to the retort and burners be thereby
of
out off.
In the accompanying drawings:
A, represents the shell enclosing the retort or vapor-generator of the engine; _Bits
working-cylinder; C its valve-chest; D the shaft; D₁ the fly-wheel; E the
condensing-coil; F the condensing-tank; G the naptha tank or reservoir; and H the
naptha feed-pump.
1, represents a pump driven by the engine and whose discharge-pipe J is connected
with the condensing-tank F so that the cold water delivered from the pump is made
to pass over and around the condensing-coil E before it is finally conveyed to the
receiving main or reservoir by the pipe K,—see Figure 2,

page_text: The cylinder-head, and also the head L by which the main shaft of the engine is
coupled to the water-pump I, and to the feed-pump H, together with the cranks and
eccentrics on the main-shaft operating the cross-head and valve-gear, see Figure 3,-
are all enclosed within an air-tight metallic casing O, so that any escape of vapour or
naptha at the joints of the piston-rod is caught and retained within said casing, and
the moving parts are lubricated thereby.
The generator is of customary form, consisting chiefly of a series of superimposed,
connected, flat, helical coils i, i, i, constituting a retort R, which is exposed to the
flames of a vapor-burner 2, placed beneath them within the casing A. This burner
is supplied with vapor from the retort, said vapor being admixed with air by means of
an injector or aspirator, 3. The remainder of the vapor passes directly from the retort
to the valve chest C, through the central vertical tube 4 and thence to the working-
cylinder B of the engine to produce, in the usual manner, by its expansion therein,
the reciprocating movements of the piston. The vapor exhausted from the cylinder at
each stroke of the piston is discharged into the condensing-coil E which, being kept cool
by the flow of water from the pump I, through the condensing-tank or chamber F,
will cause the vapor passing through the coil to condense back into its original liquid
form in readiness to be returned to the retort.
The feed-pump H,-
-see Figure 3,-is connected directly with the lower end of the
retort R, by means of a pipe S,-see Figure 1 and dotted lines Figure 2, and also
with the supply-tank or reservoir of naptha G, by means of a pipe M governed by a
valve N.
In the use of engines of this class for propelling boats the condensing-tank is not
needed, the condensing pipes E being led outside of the boat to be submerged in the
water in which it floats.
In the foregoing particulars the engine as described is of a well known type and
presents no special features of novelty.
My invention relates to the construction and use in connection with an engine of
this description, in which the vapor of naptha or other inflamable liquid or compound
is employed, of a safety-device which consists of an air-tight vessel or chamber P,
―see Figures 1 and 2,-connected at its lower end directly with the feed-pipe M,
(extending from the naptha supply-tank or reservoir G, to the naptha feed-
pump H), at a point intermediate the feed-valve N and the pump, and so adjusted
as that, so long as there remains any naptha in the reservoir and the feed-pipe
valve N is open, there shall be a supply in the chamber sufficient to cover the
opening of the feed-pipe therein.
The discharge end of the condensing-coil or pipe E, is carried to the upper end
of the chamber P by means of a pipe T which opens therein. A vent-tube, W,
of much smaller diameter, is carried from the upper end of the chamber to the
top of the naptha-tank G, or to some other point at which the free vapor of
naptha escaping through said tube may be discharged with entire safety.
The casing L is also connected with the chamber P by means of a vent-tube V,
which may be connected however for convenience with the pipe T leading to said
chamber as shown in Figure 2.
In the operation of the engine fitted with my improved safety-device, so long
as the condenser-coil or pipe E is properly cooled by a supply of water thereto,
so that the condensation of the hot vapor exhausted and discharged from the
working cylinder is properly effected, the condensed liquid in the coil or pipe is
driven forward as it collects by means of the pressure of the vapor entering the
pipe, and is discharged into the safety-chamber P from whence it is drawn by
the action of the pump H, and returned to the retort R; the deficiency in the
supply thus obtained due to the amount of vapor consumed in the burner 2, being
made up by the admission of the needful amount through the valve N from the
tank G.
It is evident that so long as the condenser works properly, so that the exhaust vapor
from the engine is converted into liquid naptha and the feed-pump is fully supplied
thereby, there is no danger whatever due to the presence of vapor in the engine,

page_text: But in case the condenser fails to operate properly from any cause, as from a
failure of the water supply from the pump I to the condensing tank F, so that the
exhaust vapor passes through the condensing coils and is discharged as vapor into
the vessel P, its pressure therein will displace and drive back the naptha therefrom
through the valve N, or otherwise will vaporise it by its heat and will thereby operate
to effectually destroy the action of the pump so that it will no longer operate to draw
a supply of naptha from the tank to be forced into the retort and burners, in con-
sequence of which the movements of the engine will at once be arrested. This
automatic action of the vapor will take place the moment any escape thereof which
might operate to produce a fire or an explosion about the engine or in the tank begins
to occur.
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 :-
The combination with the condenser or condensing coil, feed-pump, supply-pipe and
supply-tank, in a naptha-engine, of a closed vessel substantially as described, com-
municating at its lower end with the supply-pipe between the pump and tank, and
connected directly with the condenser or condenser coil to receive the discharge
therefrom, substantially in the manuer and for the purpose herein set forth.
Dated this 20th day of November 1888.