AN IMPROVED STEAL GENE- RATOR
Year: 1836

page_text: SCHAFHAUTL'S SPECIFICATION.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
SCHAFHAÜTL, of Sheffield, in the County of York, Gentleman, send greeting.
WHEREAS His present most Excellent Majesty King William the Fourth,
by His Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Sixteenth day of February, in the sixth year of His reign,
did, for Himself, His heirs and successors, give and grant unto me, the said
Charles Schafhautl, His special licence that I, the said Charles Schafhautl,
my exors, adñiors, and assigns, or such others as I, the said Charles Schafhautl,
my exors, adñiors, or assigns, should at any time agree with, and no others,
from time to time and at all times during the term of years therein expressed,
should and lawfully might make, use, exercise, and vend, within England,
Wales, and the Town of Berwick upon Tweed, and in all His Majesty's
Colonies and Plantations abroad, my Invention of "AN IMPROVED STEAL GENE-
RATOR;" in which said Letters Patent is contained a proviso obliging me, the
said Charles Schafhautl, by an instrument in writing under my hand and seal,
particularly to describe and ascertain the nature of my said Invention, and in
what manner the same is to be performed, and to cause the same to be inrolled
in Ilis said Majesty's High Court of Chancery within six calendar months next
and immediately after the date of the said recited Letters Patent, as in and by
the same, reference being thereunto had, will more fully and at large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
Charles Schafhautl, do hereby declare the nature of my said Invention to
consist in a steam generator formed of two cylinders, placed either one beside
the other or one within the other, and so arranged with reference to the
furnace or fire as to expose a very extended surface to the action of the heat
therefrom, while jets of air, and in some cases steam, are continually feeding
the fire and encreasing combustion therein; and in further compliance with
the said proviso, I, the said Charles Schafhaut, do hereby describe the manner
in which my said Invention is to be performed by the following statement thereof,
reference being had to the Drawing annexed, and to the figures and letters
marked thereon, that is to say:-
DESCRIPTION OF THE DRAWING.
Figure 1 is a sectional elevation of one of my improved steam generators
where the two cylinders before alluded to are placed side by side. A and Bare
two cup ends, made of wrought iron plates half an inch thick, and flanged on to
the bottom part of the working cylinders G, H, which are bell-shaped at their
lower ends for the purpose.
These cup ends are placed in the fire-place
(Figure I, F,) which consists of a box made of iron plates, lined inside with thin
fire-bricks of one and a half inch in thickness, which lining is distant from the
cylinder about five inches (see ground plan of the fire-place), and the box must
be adapted to the shape of the two cylinders, as shewn in such ground plan
(Numbers 4.) This box is surrounded on the sides, except the top and bottom
parts, with a casing, leaving a hollow space or air chamber of about three inches
wide (Figure 1, a). This hollow space during the working of the engine is filled
with compressed air, and serves as an air regulator to admit the compressed
air into the fire. The sides of the furnace are perforated with twelve small
tubes (c) or openings, which are directing the steam of compressed air against
the bottom parts of the cup ends in about an angle of twenty degrees; in the
bottom of the furnace, just below the cup ends of the cylinders, are two round
openings containing a fire grate, which may be closed if required; the two cup
ends A and B are fixed to the working cylinders G, H, as before described,
and the working cylinders are fastened in the large iron frame I, which frame
supports the whole weight and resistance of the engine. The two pistons K, K,
are hollow boxes, filling up the whole diameter of the working cylinders as air-
tight as possible; the pistons are cast from the very hardest quality of pig
metal. On the top of the hollow boxes are screwed the piston rods L, L; to
the upper end of the working cylinders G, H, are fixed stuffing boxes d, d, as
large in size as the diameter of the working cylinder, in which stufling boxes

page_text: the pistons are working up and down air-tight. To the upper end of the working
cylinders are fastened two blowing cylinders M, M; the top of the blowing
cylinders shut with a lid; through the middle of the lid works the air-tight
piston rods L, L. On one side of the diameter of the lid is a
valve opening
inside, and on the other side of the diameter is a valve opening outside into the
connecting air passages f, f, which lets the air into the large horizontal air box N,
from which air box the compressed air is driven down through the passage O
to the air regulator surrounding the fire box. On the top side of the air box N
is a large safety valve, opening outside, and balanced by means of an horizontal
lever mounted with a sliding weight to regulate the pressure on the valve
from nought to every advantageous weight.
To make the pistons work, a certain quantity of water is alternately ejected
into each of the cup ends through a jet pipe g, which spreads the water down-
wards against the sides and bottom of the cup ends. To inject alternately the
water into the cup ends in certain quantities I have constructed the following
machinery:-The two jet pipes, Figure 2, 7, 9, are carried outside the furnace
to the front of the working cylinders, and each are used for both the following
purposes, that is to say, not only for injecting the water, but also for the steam
to escape through. To effect this double purpose, to the upper end of each pipe
is fixed a stop-cock, the plug of which has a hole through it, as shewn in the
Drawing (Figure 2), of the size of the internal dimensions of the steam escape
pipe; the four sides of the cases of the plug are perforated with four holes
(Figures 2 and 3, 0, 1, m, and 7), and at each stroke of the piston two holes
of the casing must coincide with the two openings of the right angular hole of
the plug, Figures 2 and 3. 1 is connected with the injecting and escape pipe;
m is connected with the horizontal feeding pipe P (Figures 2 & 3), from the
middle of which feeding pipe ascends the vertical pipe to the feeder Q, which
is the reservoir or supply of water; q is a stop-cock in the feeding pipe (P), to
regulate the quantity of water; s, s, are two holes in the vertical pipe (r), to
allow the water in the reservoir Q to run down; and T is a piston, which fills
up the vertical piper, to force the first injection into one of the cup ends; and
is a valve to allow the water to run from the feeder into the horizontal feeding
pipe, and prevent the water from being driven backwards. The two plugs turn
together in the same direction through a space of three quarters of a circle;
during the rising of one of the pistons the plugs turn forwards, and during the
descent of the piston the plugs turn backwards; the relation of the two angular
holes in the two plugs, in each of their three different pistons, is shewn by the
Drawing, Figures 2, 3, and 4. Suppose the injection is made into the cup
end A, the water is converted instantly into steam of an elastic force, which
depends upon the quantity of injected water, and drives the piston forwards,

page_text: expanding itself while the piston of the other cylinder is descending; when the
piston of the cylinder A has nearly reached the top, both cocks, turning a
quarter of a circle, will then be in the position, Figure 1I.; the way for the
steam, which is escaping with great force from the cup end A, is opened
to the feeding pipe, and the steam presses against the water in this pipe
and forces it through the stop-cock of the cylinder H, in Figure 2, into the
cup end B; as soon as this injection is made the two stop-cocks turn a
quarter of a circle in the direction of the arrows, and the communication
of the cup end B with the injecting pipe is stopped and the passage O of
the cup end A opened, Figure 3, so as to let escape the remaining quantity
of steam; during the descent of the piston the escaping steam, by means of
The relative position of
the steam pipe, is driven back to the water reservoir.
the two steam cocks at this time will be as in Figure 3; the steam is escap-
ing through o in the line of the arrow, and the emptied horizontal feeding
pipe P is filling itself with water for a new injection through the middle valve
(Figure 2, ), and the communication pipe p of the cock which belongs to the cup
end B. During the rising of the piston in the cylinder 1, a few moments before
this piston has arrived near the top of the cylinder, the piston turns both cocks
backwards, and the play of the cocks is the reverse of the above described,
Figure 4. To produce the motion of the cocks each cock bears on the top of
its plug a cog wheel, Fig. 4, which two cog wheels are turned by a larger one,
To this large wheel is attached
which is fixed between the two smaller ones.
an iron rod which reaches to the piston rod, and is moved upwards and down-
wards by this piston rod with the beginning and ending of each rise and fall of
the piston rod, in the same manner as the air pump rod of Watt's pumping
engine opens and shuts the valves. The present Drawing of the engine is
calculated for an engine of twenty-eight horse power; the quantity of water to
be injected in this as well as in engines of all other dimensions should never be
more than to cause a pressure of sixteen atmospheres when the piston is in its
highest position. The steam generators must always be surrounded with fuel,
and for that purpose such a feeder as is in general use for common engines is
well adapted for this engine. To preserve the outside of the cylinder from
burning I have welded to the outside of it a thin sheet of platina. If the iron
and thin sheet of platina are heated in a pure charcoal fire till the iron has acquired
a good welding heat, the iron and platina will be found to weld very casily
together. Platina, which is made from platina sand in the dry way, and conse-
quently contains a certain quantity of iridium and other metals of platina
sand, is much preferable to the chemical pure platina. Should, however, the
platina in a large scale be found too expensive, a coating of paste, made of
Stourbridge clay or powdered cinders from charcoal fineries, mixed with a little

page_text: borax and drawn on the surface of the red hot metal cylinder, prevents the
cylinder from being injured by the three following attacks:-First, from the
sulphur of the coke, which converts the surface into sulphurate of iron; secondly,
from the carbon of the coke, which causes a very quickly melting carburet of
iron; and, thirdly, from the oxygen of the atmosphere, which burns or oxydizes
the iron. The surface of the inside of the cylinder when very highly heated
in the first state during the dropping in of the water is quickly coated with black
oxyd of iron, which melts and makes a glassy surface, and preserves the iron
as well as the water from further decomposition.
Figure 6 is a side elevation of one of my improved steam generators with a
steam chamber as in the common high pressure engines. In this case tho
furnace must be of a semicircular from the bottom grate, opened and surrounded
with six or twelve drift holes No 6, 6, just above the twelve blowing pipes Fig 5
and 6. A small jet of the escaping steam is let through the bottom grate v
into the highly ignited fuel; the steam is then immediately decomposed; the
oxygen of the water combines with the coke's, increasing its heat, and the
hydrogen escapes burning in a large light blue flame. The two double cylin-
ders C and D, shewn in the cross section Fig 7, are placed one within the other
for this purpose, and made from best copper or iron plates, and of the strength
commonly used for high pressure engines of five or six atmospheres. The smallest
of these double cylinders D is placed inside the larger one, and fixed with
its top line w to the inner line of the largest cylinder C, as shown in Fig. 7.
The dark shades R, S, are the spaces for the draught, through which the flames
go, and T is the space between the sides of the largest cylinder and its casing,
through which the flame and air return into the chimney fixed over the fire-place,
seen best in Figure 5; the current of air drives the flame through the spaces R, S,
and returns through the flue T which surrounds the fire-place into the chimney
which is fixed over the fire box, and causes, through the additional heat of the
fire box, a very powerful draught.
Figure 8 is a longitudinal section of Fig 6 and 7. Fig. 9 is the end of
the two connected cylinders opposite the fire-place, surrounded by the casing of
iron plates T, T. N° 2 and 3 are the feeding pipes, which feed the cylinders
C and D with water through the large central pipe Y, which is longer than
the two large cylinders C and D, and touches the back side of the casing T, T.
No 1 lets the steam from the cylinder Y into the steam chamber U, U. 5, 2,
in Fig 8 and 9, are two steam communicating pipes. Z, in Fig. 8, is the
water cylinder, which receives its water from a force pump. When the cylinders
are constructed of copper I fill up the spaces between the double cylinders
in Fig. 7 to the line 2, y, with spiral rollers of a net made from zinc wire, of
the thickness of about one sixteenth part of an inch, and the loops of this nos

page_text: are about half a square inch in width; but if the cylinders are constructed of
iron I bind the spiral rolls of zinc with copper wire of the same dimensions as
the zinc wire. The evaporation begins very rapidly from the surfaces of those
net rolls without generating large bubbles or an ebullition, and likewise any
incrustation of the cylinders is prevented; and the thick mud can be washed out
very easily.
Now whereas I claim as my Invention the steam generators herein-before
described, and such my Invention being, to the best of my knowledge and belief,
entirely new, and never before used within that part of His said Majesty's United
Kingdom of Great Britain and Ireland called England, His said Dominion of
Wales, and Town of Berwick upon Tweed, or in any of His said Majesty's
Colonies or Plantations abroad, I do hereby declare this to be my Specification
of the same, and that I do verily believe this my said Specification doth comply
in all respects, fully and without reserve or disguise, with the proviso in the said
herein-before in part recited Letters Patent contained. Wherefore I do hereby
claim to maintain exclusive right and privilege to my said. Invention.
In witness whereof, I, the said Charles Schafhautl, have hereunto set my
hand and seal, this Fifteenth day of August, One thousand eight hundred
and thirty-six.
AN
REMEMBERED,
August,
year of our Lord 1836, the aforesaid Charles Schafhaut came before our said
Lord the King in his Chancery, and acknowledged the Specification aforesaid,
and all and everything therein contained and specified, in form above written.
And also the Specification aforesaid was stamped according to the tenor of the
Statute made for that purpose
Inrolled the Sixteenth day of August, in the year of our Lord One
thousand eight hundred and thirty-six.