Improvements in Instantaneous Steam Generators.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in Instantaneous Steam Generators.
I, SIR CHARLES STEWART FORBES, Baronet, Castle Newe, Strathdon, Aberdeen-
abne, Gentleman, do hereby declare the nature of this invention to be as
follows.
My invention consists in improvements in steam generators, and relates more
particularly to that class in which steam is instantly generated by the injection
of small quantities of water The construction is as follows I form from mild
steel or on plate, or I may piеes from or cast in any suitable metal two tube
plates, the thickness being proportionate to the working pressure Each of
these is flanged, bent 1ound, or otherwise fashioned, so as to form a recess, and
fitted with a steam-tight cover which is secured with steel or other studs or
bolts and nuts The tube plates are drilled and reamered out, and fitted with
steel or other suitable metallic tubes which are carefully expanded into the holes
in each tube plate until steam-tight Before the tubes are passed into the holes
dilled to receive them, a series of cylinders formed of aluminium or other metal
suited to my purpose are threaded upon each tube, allowance being made for
free expansion
A recess 18 formed concentric with each hole in the tube plate
by means of a pin drill or similar tool, so as to form a fair seating for a washer,
the underside of which is cut away in part, so that it sits upon three or more
feet; a central hole 18 bored or cored in each washer slightly smaller than the
internal bore of each tube, and a rod of diawn aluminium or equivalent metal
screwed at each end passed through each tube and pan of washers, and secured
by nuts which are screwed up to the flat face of the washers. Stout the bolts
pass through the side plates and hold the parts igidly together, and a pump
and steam connection is provided. A boiler or generator constructed as described
may be fined by means of solid, liquid or gaseous fuel, the furnace casing or
shrouding being arranged accordingly.
The operation is as follows A fire being lighted, the flame on heat plays
upon the metal cylinders threaded upon the tubes, until they are sufficiently
heated up
A very small quantity of water 18 then forced into the recess or
water space on one side by a pump or other means, the water 18 forced beneath
the washers formed as described and between the metallic rods and the inner
wall of the tubes, and is instantly converted into steam at a very high temperature
which escapes from under the washers at the opposite end of the tubes into
the recess or steam space, and 18 then conducted to a dome or in some cases
direct to the steam engine, pump or equivalent apparatus The object of the
aluminium cylinders 18 to protect the tube from the direct action of the flame
or fire and provide a store of heat

page_text: Improvements in Instantaneous Steam Generators.
I, SIR CHARLES STEWART FORBES, Baionet, Castle Newe, Strathdon, Aberdeen-
shire, Gentleman, 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.-
My invention consists in improvements in steam generators, and relates more
particularly to that class in which steam is instantly generated by the injection
of small quantities of water The construction is as follows; -I form from mild
steel or iron plate, or I may press from or cast in any suitable metal two tube
plates, the thickness being proportionate to the working pressure Each of
these is flanged, bent round, or otherwise fashioned, so as to form a recess, and
fitted with a steam-tight cover which is secured with steel or other studs or
bolts and nuts The tube plates are drilled and reamered out, and fitted with
steel or other suitable metallic tubes which are carefully expanded into the holes
In each tube plate until steam-tight. Before the tubes are passed into the holes
dulled to receive them, a series of cylinders formed of aluminium or other metal
suited to my purpose are threaded upon each tube, allowance being made for
fice expansion
A recess is formed concentric with each hole in the tube plate
by means of a pin dull or similar tool, so as to form a fan seating for a washer,
the under side of which is cut away in part, so that it sits upon three or more
feet, a central hole is bored or cored in each washer slightly smaller than the
internal boie of each tube, and a rod of diawn aluminium oi equivalent metal
screwed at each end passed through each tube and pan of washeis, and secured
by nuts which are sciewed up to the flat face of the washers Stout the bolts
pass though the side plates and hold the parts ngidly together, and a pump
and steam connection is provided A boiler or generator constructed as described
may be fixed by means of solid liquid or gaseous fuel, the furnace casing or
shouding being aanged accordingly
The operation is as follows A fine being lighted, the flame or heat plays
upon the metal cylinders threaded upon the tubes, until they are sufficiently
heated up
A veir small quantity of water is then forced into the recess or
water space on one side by a pump or other means, the water 18 forced beneath
the washers formed as described and between the metallic rods and the inner
wall of the tubes, and is instantly converted into steam at a very high temperature
which escapes from under the washers at the opposite end of the tubes into
the recess of steam space, and is then conducted to a dome or in some cases
duect to the steam engine, pump or equivalent apparatus The object of the
aluminium cylinders is to protect the tube from the direct action of the flame
or fire and provide a store of heat
To enable iny invention to be more clearly understood I will more fully describe
the same with reference to the drawing in which.-
Fig 1 Is a longitudinal section of a boiler constructed in accordance with
my improvements
Fig 2 Ir a half mid section of Fig 1
Fig Shews detail of rods tubes and aluminium rings
Fig 4 Shews in detail washer
Fig 5 Shews the tie bar and nut
In the drawings 1, 1° are the tube plates, these may be pressed or stamped
fiom mild steel or on plate or they may be cast in mild steel, gun metal or
other tough and suitable metal the thickness being proportionate to the working
pressure
Each of these tube plates is flanged as at 2 and fashioned so as to

page_text: gion
form a recess 3. The tube plates are drilled and reamered out as at 4 and
the flanges dilled for the bolts 5 and tie rods 6 by which the two tube plates
and covers are held together The outer ends of the holes 4 opening into the
recess 3 formed between the tube plate and cover are enlarged concentrically
by means of a pin dill or equivalent tool as at 4ª so as to form a recessed seat
for the washers 8 The underside of each of these washers 18 cut away in part
as at 9 see Fig. 4 so that it sits in the recess on three or more points on feet.
A central hole 4b 18 formed in each washer by boring on like means slightly
smaller than the bore of the boiler tubes 10. Before the steel or other tubes 10,
are passed into the holes drilled to receive them in the tube plate a senes of
cylinders formed of aluminium, cast iron, copper or other metal 11 suited to
my purpose are threaded upon each tube, allowance being made for their expan-
The object of these cylinders is to protect the tubes from the direct action
of the flame, and to store the heat which when thin tubes are employed alone 18
dissipated to a greater or less extent by the injection of cold water from the
pump The tie iods 6 are next placed in [osition and the tube plates forced by
means of the nuts 14 against the shoulders, 16 see Fig 5. The tubes 10 are
then expanded into the holes in each tube plate and then 1ough ends removed
Each pan of washers 8 19 next put into its recessed seat 4" and a iod of aluminium
copper or other metal 12 slightly smaller than the internal bore of the tube
and capable of retaining heat, inserted The ends of the rods are threaded as
at 13 passed through each tube 10 and washer 8 nuts 14" being run upon the
threaded ends of the iods and screwed up to the face of the washers, the rods
being thereby held in a position central to the tube When the whole of the
internal rods are in position the nuts 14 are run back and off the screwed ends
of the tie rods 6 the covers 7 shipped over the same and secured by the steel
bolts 5 and nuts 14 on the tie rods The drawing shows a boiler having the
tube plates and covers cust 11 gun metal which if it consists of
what is known as Admiralty mixture I have found to answer well The
tube plates and covers may however be pressed stamped or forged out of steel
o on plates if required In the dhawings the cover 18 cored and tapped as
at 17 and the cold water injection pipe 17b screwed therein and connected to the
pump The steam issues from a cored hole 17' in the upper part of the cast tube
plate this being tapped and a steam pipe 17 screwed therein and connected to
the engine steam pump on the like If the tube plates and covers are pressed
or forged, the covers are dilled and tapped in any suitable position and the
steam and water injection pipes 17h, 17, screwed therein The boiler when filed
by oil is preferably fitted with feet 18 as shewn A double shroud of thin sterl
plates 19 19 18 secured by screws 5" to the tube plate covers or other convenient
part
And a funnel 20 fitted for the escape of the furnace gases
The space
between the shrouds may be left open so that the air cuculates fully through it,
01 it may be packed with asbestos, wool 22 or equivalent non-conducting
material A hand or firing hole 23 and door 24 are formed in the shrouding
for starting the vapoulizing or other oil burner when such is employed or attend-
ing to the coal coke or other fire replacing it, a suitable giate, fine bars and ash pit
being formed beneath.
The operation of my invention is as follows.
A fine being lighted, the flame or heat radiated therefrom plays upon the
metallic cylinders surrounding the tubes, until they are sufficiently heated up
The force pump is then operated, the water therefrom being forced beneath the
washers and into the small annular spaces between the rods and the inner wall
of the tubes is instantly converted into steam at a very high temperature which
escapes from under the washers at the opposite end of the tubes, into the tube
space, and 18 then conducted to the engine, steam pump or other apparatus
operated by it, by the pipe 17° it will be readily understood that constructionally
a boiler of this type may vary greatly and that I do not especially bind myself

page_text: to the particular type shewn in the drawings for the purpose of describing my
invention.
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 18
1 In or with a tubular generator the combination and use of metallic cylinders
threaded upon the exterior of said tubes with a metallic rod passing through
the interior of each tube and supported by the washers and nuts mounted in
the tube plates substantially as shown
2. In or with an instantaneous steam generator, the combination and use
of the particular form of washers, employed for supporting the threaded rods
and the nuts thereon, shaped so as to compel the injection water to pass beneath
them, into the annular space between the exterior of said rods and the interioi
of said tubes, substantially as shewn
Dated this 10th day of Nowh 1000
FRANCIS M. ROGERS,
Agent for the Applicant, 21, Finsbury Pavement, London, EC.,