Improvements in Steam Generators.
Year: 1897

page_text: Date of Application, 5th Feb., 1897
Complete Specification Left, 19th Oct., 1897-Accepted, 4th Dec., 1897
Improvements in Steam Generators.
I WILLIAM HENRY DUGARD of Vulcan Mills, Bridge Street West, Birming-
ham in the County of Warwick Metal Tube and Wire Manufacturer do hereby
declare the nature of this Invention to be as follows:―
My invention relates to steam generators, heated by the combustion of liquid
or gaseous fuel, principally for use in the generation of steam for the motors of
common road carriages. steam launches and the like; and consists of the con-
struction and arrangements or combinations of parts hereinafter described of the
said steam generators, whereby the generation of steam is very rapidly effected
and the supply of liquid or gaseous fuel and air to the burner or combustion
space of the steam generator as well as water to the said generator is automatically
controlled.
I will describe my invention in connection with a steam generator heated by
a liquid hydro-carbon such for example as petroleum.
In carrying my invention into effect I arrange in a practically closed cylinder
or casing three (or more) concentric helical coils of metallic tubing for containing
the water and steam of the generator. The outer and intermediate or middle
helical coils are compact or close helices, the intermediate or middle coil con-
stituting a tubular division separating the inner or axial part of the cylinder or
casing from the outer part in which the outer compact helix is situated, the
intermediate or middle coil plassing at top into an involute coil occupying the
upper space of the casing. The inner coil is in the form of an open helix and
occupies the axial space of the cylinder or casing. The several coils are com-
nected in series or pass into one another in the following manner and the feed
water is supplied to the said coils also in the following manner. ine outer
coil is connected at bottom to the feed water supply pipe. The said ouser coil
passes from the top by a Ț shaped connection into the bottom of the inner open
coil which inner open coil passes at top by another Ṭ shaped connection into
the bottom of the intermediate or middle coil. The top of the last named or
intermediate coil passes as hereinhefore described/into the involute coil which
is connected to the steam tube or passage of the engine or motor in connection
with the steam generator.
In the bottom of the casing of the steam generator is an axial opening into
which the jet of the oil supply tube and also a pilot burner used in combination
with the same open; and the outer space of the casing opens at bottom. into a
flue, an exhaust draught in which is maintained preferably by a rotary fan.
Over the axial opening referred to in the bottom of the casing an inverted per-
forated cap preferably of plumbago, is arranged.
The pilot burner is capable of being readily removed and refixed for the purpose
of lighting it. The oil supplied to the oil jet is sprayed by an axial jet of steam
or air into the combustion space of the steam generator, air being also supplied
to the said space in the manner hereinafter described. When the mixture of
combustible spray and air is ignited by the pilot burner the frame produced
passes through the perforations in the inverted plumbago pot and impinges on
the inner side of the intermediate or middle coil of piping of the steam generator

page_text: the said flame completely enveloping the inner coil of the said generator. The
gaseous products of combustion rise to the top of the casing and pass over the
top of the middle coil into the outer space of the casing in which the outer coil
is situated. The said products of combustion are drawn down the said outer
space of the casing by the exhaust in the flue at the bottom of the same and
escape by the said flue into the atmosphere. In this way steam is rapidly
generated and supplied by the involute coil to the motor or engine of the carriage
or launch.
The supply of combustible oil to the spray jet is regulated as follows:-The
mouth of the oil supply pipe is controlled by a rising and talling valve on the
end of a piston rod the piston of which occupies and is pressed by a coiled spring
in a cylinder in the direction proper to raise the said valve and open the mouth
of the oil supply-pipe. The top or upper side of the piston is in connection with
a short corrugated pipe or inner cylinder open to the steam supply pipe of the
steam. generator and the length of the slid corrugated pipe is increased or
diminished according to the pressure of the steam. When the pressure of the
steam increases the piston and piston rod are pressed down against the action
of the spring and the mouth of the oil supply pipe is partially closed. In place
of the corrugated tube described of the automatic regulator, a Bourdon tube or
other steam controlled regulator may be employed.
The supply of air to the combustion space of the steam generator is simul-
taneously regulated by a throttle valve in the air admission passage, the said
throttle valve being oporated, by a lever and connecting rod, through the piston
or valve rod of the oil supply regulator.
The supply of feed water to the outer helical tube of the generator is auto-
matically controlled in the following manner.
A continuous supply of water from a water tank or surface condenser or both
is maintained so long as the steam generator is in use by a feed pump and the
supply of water is regulated by an automatic valve arranged in the suction pipe
of the pump or supply pipe from the tank. The said valve is opened and closed
by the steam pressure generated in a hermetically sealed pipe or tube part of
which is placed in the outer end of the involute steam coil of the generator. The
pipe or tube is nearly filled with water before the hermetic sealing of the said
tube is effected. The outer end of the said hermetically sealed tube terminates
in a corrugated tube and rod of the kind hereinbefore described by which a
valve is pressed on or raised from off-its valve seat in the suction pipe of the
pump according as the pressure of the steam in the hermetically sealed tube is
diminished or increased.
By this arrangement when the superheated steam in the involute coil exceeds
the desired normal temperature the coresponding pressure produced in the
hermetically sealed tube causes the water supply to the feed pump to be increased.
On the diminution of the temperature in the involute coil the reverse action takes
place and a reduced quantity of water is supplied to the feed pump.
Or in place of the arrangement described a Bourdon tube or other equivalent
device may be employed to control the feed water regulating valve.
Dated this fifth day of February 1897.
W. T. WHITEMAN
Agent for the Applicant.

page_text: declare the nature of my invention and in what manner the same is to be per-
formed to be particularly described and ascertained in and by the following
statement:—
My invention relates to steam generators, heated by the combustion of liquid
or gaseous fuel, principally for use in the generation of steam for the motors of
common road carriages, steam launches and the like; and consists of the con-
struction and, arrangements or combinations of parts hereinafter described of the
said steam generators, whereby the generation of steam is very rapidly effected
and the supply of liquid or gaseous fuel and air to the burner or combustion
space of the steam generator as well as water to the said generator is automatically
controlled.
I will describe my invention in connection with steam generator heated by
a liquid hydro-carbon such for example as petroleum.
In carrying my invention into effect I arrange in a practically closed cylinder
or casing three (or more) concentric helical coils of metallic tubing for containing
the water and steam of the generator. The outer and intermediate or middle
helical coils are compact or close helices, the intermediate or middle coil con-
stituting a tubular division separating the inner or axial part of the cylinder or
casing from the outer part in which the outer compact helix is situated; the
intermediate or middle coil passing at top into an involute coil occupying the
upper space of the casing. The inner coil is in the form of an open helix and
occupies the axial space of the cylinder or casing. The several coils are con-
nected in series or pass into one another in the following manner and the feed
water is supplied to the said coils also in the following manner. The outer
coil is connected at bottom to the feed water supply pipe The said buter coil
passes from the top by a Ț shaped connection into the bottom of the inner open
coil which inner open coil passes at top by another T shaped connection into
the bottom of the intermediate or middle coil. The top of the last named or
intermediate coil passes as hereinbefore described into the involute coil which
is connected to the steam tube or passage of the engine or motor in connection
with the steam generator.
In the bottom of the casing of the steam generator is an axial opening into
which the jet of the oil supply tube and also a pilot burner used in combination
with the same open; and the outer space of the casing opens at bottom into a
flue, an exhaust draught in which is maintained preferably by a rotary fan.
Over the axial opening referred to in the bottom of the casing hui inverted per-
forated cap preferably of plumbago, is arranged.
The pilot burner is capable of being readily removed and refixed for the purpose
of lighting it. The oil supplied to the oil jet is sprayed by an axial jet of steam
or air into the combustion space of the steam generator, air being also supplied
to the said space in the manner hereinafter described. When the mixture of
combustible spray and air is ignited by the pilot burner the flame produced
passes through the perforations in the inverted plumbago cap and impinges on
the inner side of the intermediate or middle coil of piping of the steam generator
the said flame completely enveloping the inner coil of the said generator. The
gaseous products of combustion rise to the top of the casing and pass over the
top of the middle coil into the outer space of the casing in which the outer coil
is situated. The said products of combustion are drawn down the said outer
space of the casing by the exhaust in the flue at the bottom of the same and
escape by the said flue into the atmosphere.
In this way steam is rapidly generated and supplied by the involute coil to
the motor or engine of the carriage or launch.
'
The supply of combustible oil, steam and air to the spray jet is regulated by
valves which are operated by the lengthening and shortening of a corrugated or
expansible tube open to the steam supply pipe of the generator.
The supply of feed water to the outer helical tube of the generator is auto-
matically controlled in the following manner.

page_text: A continuous supply of water from a water tank or surface condenser or both
is maintained so long as the steam generator is in use by a feed pump and the
supply of water is regulated by an automatic valve arranged in the suction pipe
of the pump or supply pipe from the tank. The said valve is opened and closed
by the steam pressure generated in a hermetically sealed pipe or tube part of
which is placed in the outer end of the involute steam coil of the generator. The
pipe or tube is nearly filled with water before the hermetic sealing of the said
tube is effected. The outer end of the said hermetically sealed tube terminates
in a corrugated tube and rod of the kind hereinbefore referred to by which a
valve is pressed on or raised from off its valve seat in the suction pipe of the
pump according as the pressure of the steam in the hermetically sealed tube is
diminished or increased.
By this arrangement when the superheated steam in the involute coil exceeds
the desired normal temperature the corresponding pressure produced in the
hermetically sealed tube causes the water supply to the feed pump to be increased.
On the diminution of the temperature in the involute coil the reverse action takes
place and a reduced quantity of water is supplied to the feed pump.
In place of the arrangement described a Bourdon tube or other equivalent
device may be employed to control the feed water regulating valve.
Figure 1 of the accompanying Drawing represents in vertical section a steam
generator constructed according to my invention and Figure 2 represents a "hori-
zontal section of the same, the said section being taken on the dotted line t,
Figure 1.
The same letters of reference indicate the same parts in both Figures of the
Drawing.
The steam generator consists essentially of a double cylindrical casing a, a
closed at top and bottom within which cylindrical casing are arranged the con-
centric helices of tubing b, c, d, through which helices or vertical coils the water
to be converted into steam is passed in the manner hereinafter described. The
space between the outer and inner walls of the double cylindrical casing is packed
with a non-conducting material for heat such for example as asbestos.
The helical coil of tubing c is close and rests on a ring like platform e on or
near the bottom a¹ of the casing a the said coil e extending to near the top of
the casing thereby dividing the said casing into two upright or vertical flues,
an inner or axial flue and an outer annular, Hue communicating with one another
at the top of the casing a. In the outer annular flue a close helical coil of
tubing b, preferably of small diameter, is arranged, the bottom end of the said
coil 6 being connected with the water supply f of the pump h.
The top end of the coil b passes down and is connected to a blow out pipe or
tube (see Figure 1) terminating the bottom of the open helical coil d occupy-
ing the inner or axial flue of the generator. The top of the said open helical
coil d terminates in a second blow out pipe or tube d² to which the bottom end
of the helical coil is connected. Both blow out pipas d¹, & are provided with
cocks as represented by which the said pipes are opened when it is desired to
empty the coils of the generator. The top end of the coil c is connected to a
horizontal involute coil y passing into the steam supply pipe of the generator.
The level of the water in the coil is determined by a down pipe c which is
opened and closed by a stop cock c².
The water in the coils is rapidly heated by the combustion of liquid fuel which
is supplied to the spray burner 7. The combustion space of the generator is formed
by arranging a perforated cap k, preferably of plumbago, over a central hole in
the bottom a of the casing, the flame and products of combustion passing through
the perforations in the said cap k into the inner or axial flue of the generator
where the said flame and products of combustion impinge on the inner side of
the coil and completely envelope the axial coil d.
The products of combustion are drawn down the outer annular upright flue
between the inner wall of the casing a and the outer side of the coil c by the

page_text: draught created in a horizontal flue n under the bottom a¹ of the generator by a
rotary fan m. The outer or annular flue of the generator communichtes-with-the-
bottom horizontal flue n by holes or perforations a³, a³ in the bottom a of the
casing.
h
Water is drawn from a water cistern or condenser or both (not shown in the
drawing) by a pump through a regulating valve o, which is automatically
operated in the manner hereinafter described, and is forced by the pump
through a check valve f¹ and through the coils b and d into the coil c where the
level at starting is determined by the pipe cand opened stop-cock c². The said
stop cock having been closed the water in the generator is heated and rapidly
converted into steam by the combustion of liquid fuel which is supplied as
follows:-
The pipe is connected to the oil or liquid fuel tank or container (not shown)
and the oil passes through the hand worked valve 1 by the flexible tuber to the
pilot burner Oil also passes by the valve 2ª to the oil conducting pipe s of
the spray burner. The valve p² of the oil supply pipe s is opened and closed by
the expansion and contraction of a corrugated tube t the interior of which com-
municates by means of the pine with the steam supply pipe i of the generator.
The upper end of the rod of the valve 2 terminates in a disc resting on a coiled
spring which tends to keep the valve in its raised or fully open position.
The valve or damper of the air inlet passage of the combustion space is
controlled by the rod of the valve 2 acting through the lever v connecting rod 1
and arm on the axis of the valve or damper w. Steam for spraying the oil
into the combustion space is conducted by the pipe from the steam supply
pipe to the spray burner 7. and the mouth of the pipe is controlled by a valve
which is opened and closed by the contraction and expansion of the corrugated
tubet acting through connecting links or levers on the said rod z. Thus, the
supply of oil, steam and air to the combustion space of the generator is auto-
matically and simultaneously regulated.
The supply of water to the coils b, c, d of the generator is similarly regulated
so that when the temperature of the steam passing from the generator exceeds
the desired normal temperature, the check valve o is further opened and the
supply of water increased and the reverse. This is effected by arranging in the
steam supply pipe a small sealed tube o containing water the said tube passing
out of the steam supply pipe and terminating in a corrugated tube or expansible
chamber (similar to that marked t) arranged in a casing o¹. The water in the
sealed tube o is converted into steam of the same or approximately the same
temperature as the steam given off by the generator, which steam in the sealed
tube acting on the corrugated tube of the valve o effects the opening and closing
of the shid valve in a way essentially the same as that described with respect to
the valve of the oil passage s.
↑
The top a³ of the generator has an axial tubular opening closed by a cap a
which on first starting the generator is removed, the products of combustion
escaping for a time by the axial tubular opening. When the pressure of the
steam generated permits of the working of the rotary fan m by the motor in
connection with the generator the cap a' is replaced when the products of com-
bustion take the course through the outer or annular flue and bottom horizontal
flue as herein before described
Although I have represented in the drawing a generator having three helical
coils only I wish it to be understood that I do not limit myself to that number as
four or more concentric helical coils may be employed without departing from
my invention:―
Having now particularly described and ascertained the nature of my inven-
tion and in what manner the same is to be performed I declare that I claim as
my invention:-
First: The construction and arrangement or combination of the steam pro-

page_text: ducing parts of a steam generator hereinbefore described and illustrated in the
accompanying Drawing, the said construction and arrangement of parts consisting
essentially of three or more vertical concentric helical coils, preferably in com-
bination with a top horizontal involute coil, the said coils communicating with
one another and with the water supply pipe, the several coils being arranged in
a cylindrical casing in the bottom of which is a liquid or gaseous fuel burner,
the flame and products of combustion from which envelope the innermost helical
coil and impinge on the middle or intermediate coil, when three coils are employed,
substantially as described and illustrated.
Secondly: The construction and arrangement or combination of parts herein-
before described and illustrated in the accompanying Drawing for automatically
regulating the supply of water to the steam generator, the said construction and
arrangement of parts consisting essentially of a sealed tube containing water
one end of which projects into the steam supply pipe of the generator and the
other end communicates with corrugated tube or expansible chamber which
by the heat of the steam generated in the sealed tube is lengthened and shortened
and thereby made to operate the valve of the water supply pipe substantially
as hereinbefore described and illustrated.
Thirdly: The construction and arrangement or combination of parts herein-
before described and illustrated in the accompanying Drawing for simultaneously
and automatically regulating the supply of oil, steam and air to the spray burner
of the steam generator, the said construction and arrangement of parts consisting
of a corrugated tube or expansible chamber open to the steam supply pipe which
corrugated tube or expansible chamber is connected directly or through gearing
with the valves of the said oil, steam and air supply passages substantially as
hereinbefore described and illustrated.
Dated the Seventh-day of October-1897
WILLIAM HENRY DUGARD.