Improvements relating to the Generation of Motive Power from Hot Water stored in Tanks, and to Apparatus therefor.
Year: 1897

page_text: Date of Application, 23rd Nov., 1897-Accepted, 5th Mar., 1898
COMPLETE SPECIFICATION,
Improvements relating to the Generation of Motive Power from Hot
Water stored in Tanks, and to Apparatus therefor.
I, HERBERT ALDEN THOMAS, of Evanston, County of Cook and State of Illinois,
United States of America, Gentleman, do hereby declare the nature of this in-
vention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:-
My invention relates to improvements in hot water storage motive power system
and apparatus.
In attempts heretofore made for deriving motive power by storage of hot water
under pressure in tanks for propelling street or other cars, difficulty has been
experienced in practical operation owing to the fact that as the hot water is
withdrawn from the storage tank for use pressure in the storage tank has gradually
liminished and the power generated by the expansion of the hot water into steam
has consequently grown continually less and less until finally the engine so
operated becomes inefficient and unreliable. And this difficulty is further aggra-
vated by the circumstance that as the hot water is withdrawn from the storage
tank for use the steam is of course thus permitted to generate or expand in the
storage tank itself and thus cause a more rapid reduction of temperature and
pressure in the storage tank and loss of power."
The object of my invention is to provide a system and apparatus of a simple
nature for deriving motive power from hot water stored in tanks by means of
which a more economical use of the stored power can be secured, and by which
the power generated by expansion of the hot water into steam may be maintained
substantially uniform during any reasonable interval or period of time that the
storage tank is required to be drawn upon for generation of motive power for pro-
pelling street or other cars or railway trains.
In my system or apparatus, and, herein my invention consists, the hot water
storage tank is maintained constantly filled with hot water under pressure, and the
steam is not allowed to expand in the storage tank itself, this important result
being secured by continually pumping the water condensed from the exhaust back
into the storage tank as fast as any water is drawn from the tank for use in driving
the engine by expansion into steam. And the temperature of the water in the
storage tank is also maintained by reheating the water of condensation as it is
forced back into the storage tank. The provision for maintaining the storage tank
filled with hot water under pressure is obtained by having, in addition to the usual
storage tank and expansion tank for the proper expansion of the hot water into
steam preparatory to entering the engine, an air tight steam condensing tank,
which is partially filled with water at a temperature lower than 212° F., and into
which the exhaust steam is conducted directly from the engine by the exhaust
pipes, and which operates to condense the exhaust steam into water as fast as it
escapes from the engine; the water of condensation being forced from this con-
densing tank back into the storage tank by a suitable pump provided for this
purpose. The storage tank is thus kept constantly filled with hot water under
pressure, and no vacant space is permitted therein for expansion of the hot water

page_text: into steam, which is thus entirely prevented. The provision for reheating the
water that is pumped back into the storage tank from the condensing tank is
attained preferably by forcing it through one or more double tubes located within
the storage tank and through which heat is passed preferably by a forced blast.
By this means a sufficiently high heat may be applied to the water of condensa-
tion as it is forced back to raise the temperature say about 40°, or from a
temperature of about 200° in the condensing tank to a temperature of about 240°,
which should preferably be maintained in the hot water storage tank. To give
time and opportunity for thus reheating the water of condensation the water
conducting tube and flue for heating the same should extend preferably the full
length of the storage tank.
By my system and apparatus it will thus be seen that the exhaust steam
escaping from the engine is condensed into water in the condensing tank and is
immediately pumped back into the storage tank, and only requires the addition of
30° or 40 of heat to bring it approximately or substantially up to its original
temperature. In practicing my invention the hot water is preferably introduced
at the water heating station or plant into the storage tank at a temperaure of
about 235° or 240° F., and under a pressure of about 350 pounds to the square
inch. And as the storage tank is kept constantly filled with water by returning
the water of condensation from the engine back into the tank, thus preventing
any expansion of steam in the storage tank itself; and as the water of condensation
is or may he reheated, it will be seen that the pressure in, the storage tank may be
maintained substantially uniform, and that the apparatus thus becomes a practical
one for supplying motiye power to street car motors, locomotives or other machines
requiring to be operated continuously for a number of hours, and this too without
any unnecessary waste or loss of power.
In the accompanying drawing, which forms a part of this Specification, I have
illustrated a diagrammatic view of an apparatus or system embodying my inven-
tion. In the drawing the invention is represented as being applied to a railway
locomotive, it will of course be understood however that it is applicable to other
motors or machines.
In the drawing A A représent the wheels and A' the frame work of a locomotive
or other vehicle. B is the storage tank, the same being preferably about six feet
in diameter and twenty-five feet in length, and adapted to be filled completely full
of hot water under pressure, the water being preferably heated to a temperature of
about 240° F., and the pressure being about 350 pounds to the square inch. CC
represents steam engines. As indicated in the drawing the engines are of the
rotary type and applied directly to the driving wheels of the locomotive, but any
other form of engine equally well adapted for use in the system or apparatus
embodying my invention. D represents a steam expansion chamber or tank into
which the hot water from the storage tank B is admitted and permitted to expand
into steam preparatory to entering the engine or engines through the steam
pipes dd. E is a throttle valve for controlling the admission of hot water into
the expansion tank 1) through the supply pipe or connection, and E¹ is a rod or
connection for operating the throttle valve. The expansion tank D may preferably
be located inside the storage tank 1, although it may be otherwise located if
preferred. Gis the closed or air tight condensing tank into which the exhaust
steam from the engine C is directly delivered through the exhaust pipe C. The
closed condensing tank G is partially filled with water, as indicated by the dotted
line g, so that the exhaust steam will be readily condensed as fast as it escapes
from the engine. Il is a steam pump for forcing the water of condensation from
the condensing tank G back into the storage reservoir B through the pipe H
leading from the condensing tank G to the pump, and pipe H2 leading from the
pump back into the storage tank B. The pipe H connects with the pipe K extend-
ing preferably about the whole length of the storage tank and surrounding a
heating pipe or flue M, so that the water of condensation as it is forced back into
the storage tank B may be reheated before it is discharged into the hot water in

page_text: the storage tank through the exit orifice k. The pipe or flue M may be heated by
any suitable means, but preferably by a liquid fuel burner N, by which gasoline
or other hydrocarbon fuel is forcibly projected under pressure into and through
the heating pipe or flue from the reservoir N. The heating pipe or flue M should
extend up through the hot water storage tank B, as indicated in the drawing, and
may preferably be surrounded by a smoke stack P. The gasoline or other liquid
fuel in the reservoir N' may be maintained under suitable pressure by an air
pump Ne
As my invention does not relate to any particular kind or construction of steam
engine, pump or valve mechanism, but may be practiced equally well with any
suitable kind or construction of these devices known to those skilled in the art, it
is not necessary for a full description and explanation of my invention to show
or describe any detail construction of these parts.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:
1. The hot water storage motive power system or apparatus, comprising in com-
bination a hot water storage tank filled with hot water under pressure, a steam
expansion chamber communicating therewith, a steam engine, a condensing tank
partially filled with water, an exhaust pipe leading from the engine to said con-
densing tank, a pump for forcing the water from said condensing tank back into
the storage tank under pressure to maintain the storage tank constantly filled with
water under pressure, and a heating pipe or fiue for reheating the water returned
to the storage tank by the pump from the condensing tank, whereby steam is
prevented from expanding in the storage tank as the hot water is withdrawn
therefrom for use in the engine, and the temperature and pressure in the storage
tank maintained, substantially as specified.
2. The hot water storage motive power system or apparatus, comprising in com-
bination a hot water storage tank filled with hot water under pressure, a steam
expansion chamber communicating therewith, a steam engine, a condensing tank
partially filled with water, an exhaust pipe leading from the engine to said con-
densing tank, a pump for forcing the water from said condensing tank back into
the storage tank under pressure to maintain the storage tank constantly filled with
water under pressure, a reheating pipe or flue for reheating the water returned to
the storage tank by the pump from the condensing tank, whereby steam is pre-
vented from expanding in the storage tank as the hot water is withdrawn for use
in the engine and the temperature and pressure in the storage tank maintained,
and a fluid fuel reservoir and burner for supplying heat to said flue or heating pipe,
substantially as specified.
3. In a hot water storage motive power system or apparatus, the combination
with a hot water storage tank filled with hot water under pressure, of a steam
expansion tank, a steam engine, a steam condensing tank into which the exhaust
is delivered from the engine, and a pump for forcing the water of condensation
from the condensing tank into the storage tank and thus maintaining the same
constantly filled with water under pressure, substantially as specified.
4. The combination with a wheeled car or vehicle of a motor apparatus therefor
comprising a hot water storage tank filled with hot water under pressure, a steam
expansion tank, a steam engine, a steam condensing tank into which the exhaust
is delivered from the engine, and a pump for forcing the water of condensation
from the condensing tank into the storage tank and thus maintain the same
constantly filled with water under pressure, substantially as specified.
5. The combination with a wheeled car or vehicle of a motor apparatus therefor
comprising a hot water storage tank filled with hot water under pressure, a stem
expansion tank, a steam engine, a steam condensing tank into which the exhaust
is delivered from the engine, a pump for forcing the water of condensation from
the condensing tank into the storage tank and thus maintaining the same con-

page_text: stantly filled with water under pressure, and a reheating pipe or flue for reheating
the water of condensation returned by the pump from the condensing tank to the
storage tank, substantially as specified.
6. The combination with a wheeled car or vehicle of a motor apparatus therefor
comprising a hot water storage tank filled with hot water under pressure, of a
steam expansion tank, a steam engine, a steam condensing tank into which the
exhaust is delivered from the engine, a pump for forcing the water of condensation
from the condensing tank into the storage tank and thus maintaining the same
constantly filled with water under pressure, and a reheating pipe or flue for
reheating the water of condensation returned by the pump from the condensing
tank to the storage tank, and a water conducting pipe contiguous to said heating
pipe or flue located in the storage tank for conducting the water from the pump
and delivering it after reheating into the storage tank, substantially as specified.
7. The combination with a wheeled car or vehicle of a motor apparatus therefor
comprising a hot water storage tank filled with hot water under pressure, a steam
expansion tank, a steam engine, a steam condensing tank into which the exhaust
is delivered from the engine, a pump for forcing the water of condensation from
the condensing tank into the storage tank and thus maintaining the same con-
stantly filled with water under pressure, and a reheating pipe or flue for reheating
the water of condensation returned by the pump from the condensing tank to the
storage tank, and a water conducting pipe contiguous to said heating pipe or flue
located in the storage tank for conducting the water from the pump and delivering
it after reheating into the storage tank, and a fluid fuel reservoir and burner for
supplying heat to said heating pipe or flue, substantially as specified.
1007
HERBERT ALDEN THOMAS.
In presence of
LEWIS E. CURTIS.
EDMUND ADCOCK.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.