IMPROVEMENTS IN THE APPLICATION OF THE PRODUCTS OF COMBUSTION IN GENERATING AND AIDING OF STEAM FOR GIVING MOTION TO STEAM ENGINES
Year: 1837

page_text: HAWKINS SPECIFICATION.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
ISAAC HAWKINS, of Chase Cottage, Pancras Vale, near Hampstead, in the
County of Middlesex, Civil Engineer, send greeting.
WHEREAS His late 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 seventh year of his reign,
did, for Himself, His heirs and successors, give and grant unto me, the said
John Isaac Hawkins, His especial licence, full power, sole privilege and authority,
that I, the said John Isaac Hawkins, my exors, adññiors, and assigns, or such
others as I, the said John Isaac Hawkins, my exors, admors, 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 and Wales, and the Town of Berwick upon
Tweed, the Invention of "IMPROVEMENTS IN THE APPLICATION OF THE PRODUCTS OF
COMBUSTION IN GENERATING AND AIDING OF STEAM FOR GIVING MOTION TO STEAM
ENGINES," communicated to me by Phineas Bennet, a foreigner residing in the
United States of America; in which said Letters Patent is contained a proviso
that I, the said John Isaac Hawkins, shall cause a particular description of the
nature of the said Invention, and in what manner the same is to be performed,
to be inrolled in His said Majesty's High Court of Chancery within six calendar
months next and immediately after the date of the said in part 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
John Isaac Hawkins, do hereby declare that the said "Improvements in the
Application of the Products of Combustion in Generating and in Aiding of
Steam for Giving Motion to Steam Engines," as communicated to me by the
said Phineas Bennet, and the manner in which the same are to be carried into
effect, are fully set forth and described in the following Specification or descrip-
tion thereof, elucidated by the Drawings hereunto annexed, as indicated by the
figures and letters of reference marked thereon, corresponding with similar
figures and letters of reference herein contained, that is to say:
The improvements consist in modifying the construction of that class of steam-
engine boilers in which atmospheric air is forced into the fire under great
pressure, and in which the smoke, gases, and other products of combustion are
delivered into the water of the boiler, to which water they give off a portion
of their heat and afterwards pass into.the.steam engine along with the steam.
The objects of the modification are, firstly, to obviate the loss of power occa-
sioned by the friction of the smoke, gases, and other products of combustion in
being forced through long, narrow, and crooked passages, as heretofore adopted,
and at the same time to avoid the liability which exists in a great degree in
those passages of their being choked with ashes, soot, and other substances driven
into them from the fire; secondly, to allow of the fire being supplied with fuel
while under the greatest pressure with which the engine is worked; and, thirdly,
to remove the ashes and clinkers from the grate while at a great heat. The
first of those objects' I effect by delivering the products of combustion from the
furnace into the boiler in an upward current with moderate velocity througli a
short, wide, and straight pipe, and then, by means of a cap valve placed over
the said pipe, deflecting the current downwards into the water around the out-
side of the pipe, the width, straightness, and shortness of the pipe at tlie same.
time being such as to afford but little attachment for soot, ashes, or other sub-
stances tending to choke the passage. And the second of those objects I effect
by placing two shutters sliding, steam and air tight, across the ordinary flue of
the boiler, at a sufficient height one above the other to allow of space between
them for as much fuel as ought to be supplied at any one time to the fire, and
by placing a pipe and cocks, by means of which a communication may be opened
from the said space to the interior of the boiler or to the atmosphere at pleasure,
whereby the pressure above and below the sliders may be alternately'equalized,
and thus that the sliders may be withdrawn with little force. And I effect the
third of those objects by making a looped appendage to the under side of the middle
of the fire bar, with an aperture into which an irod rod may be thrust to lift the
bar out of its seat and remove it from the furnace through the ash-pit. The

page_text: Drawings hereunto annexed exhibit a boiler as a sample of the manner of effect
ing the objects above mentioned in combination with various other common parts
of a steam boiler, and which common parts I do not claim, but they are inserted
merely for illustrating and shewing the connections of my improvements. A
scale is added by which the dimensions of the parts may be measured. It is
believed that two boilers of the dimensions shewn would be competent for, the
supply of an uncondensing steam engine of one hundred horses power working
with about forty pounds pressure to the inch. It is advisable for large engines
to multiply boilers rather than increase the dimensions of them. Figure 1
represents a section through the middle of a vertical cylindrical boiler, within
which is placed a vertical cylindrical furnace, from which furnace two flues arise,
one flue to allow the smoke to escape into the atmosphere when the engine is
not at work, and through which flue the fuel is conveyed to feed the fire, and
the other flue passing up from the furnace into the boiler to conduct the smoke,
gases, and other products of combustion into the water of the boiler when the
engine is at work. Figure 2, a side elevation of the boiler looking against the
ash-pit door; Figure 3, a side elevation looking against the air pipe and steam
pipe; Figure 4, section from A to B of Figure 1, with a view of the parts
seen below the section; Figure 5, section from C to D of Figure 1, shewing
the flanch of the slide box, which is bolted on to the top of the boiler, as being
partly inwards and partly outwards; Figure 6, section from E to F of Figure 1,
with a view of the parts seen below; Figure 7, section from C to H of Figure 1,
with a like view; Figure 8, profile of a fire bar and a handle passed through
the appendage at the middle of the bar; Figure 9, cross section of the fire
bar through the appendage; Figure 10, two views of a scraper to clear the
ashes and clinkers from the grate. The same letters of reference signify the same
parts in all the Figures. a represents the outer cylindrical casing of the boiler,
made of sheet iron rivetted together; b, the cylindrical casing of the furnace,
made of sheet iron or sheet copper rivetted together; c, the bottom of the boiler,
made spheroidal in order to be capable of resisting great pressure from within;
d, the top of the boiler, made flat under the flanches of the flues and spheroidal
at the sides of those flanches; c, .the bottom of the furnace, made flat, because
the pressure is nearly equal.on each side on account of a free communication
between the furnace and the boiler; f, the top of the furnace, from which the
two flues arise; g, g', a flue for the smoke to escape through when the engine
is not at work; h, the two sliding shutters for stopping the flue g, g', when the
engine is at work, leaving a chamber g¹ between the two shutters for a charge.
of fuel, the lower shutter to stop the flue while the chamber is being charged
with fuel, and the upper shutter to stop the flue in order that the fuel may be

page_text: discharged on the fire without affecting the pressure from within the furnace;
k, two springs fastened to the under side of the shutters to keep them up against
the under surfaces of the boxes in which they slide, and with which surfaces
the sliders must be ground air and steam tight at the parts contiguous to the
flues, the points of the springs resting on ledges at each end of the slide boxes.
There must be four springs to each shutter, one near each corner. 7, toothed
racks across the under side at the middle of the sliding shutters, by which
the shutters are moved in toothed pinions acting in the racks to slide the
shutters; n, spindles and winches for turning the pinions m; p, stuffing boxes,
through which the spindles n work, steam and air tight; q, boxes and doors in-
closing the sliders shutters to prevent the escape of air or steam. In Figure 2
the lower door is removed to allow of a view of the shutter, rack, pinion,
and springs. r, a curved pipe, forming a communication between the fuel
chamber and the furnace when the top slider is shut to produce an equal
pressure on each side of the lower slider, in order that it may be easily with-
drawn to discharge the fuel on to the grate; s, a stop-cock to cut off the com-
munication between the furnace and the fuel chamber while the chamber
is being charged with fuel; t, a cock for allowing the compressed gases
and vapours to escape from the fuel chamber into the atmosphere, in order
to take off the pressure under the upper slider, and allow it to be easily with-
drawn for the purpose of introducing fuel. The slide boxes together with
the fuel chamber are made of cast iron, in three pieces bolted together, and
two doors are bolted on, as is quite obvious in the Drawings. The lower part
of the flue within the boiler is of sheet iron or sheet copper rivetted together.
u, the smaller flue or pipe for the products of combustion to pass through into
the water of the boiler when the engine is at work; v, a cap valve for shutting
the end of the pipe u to prevent the water of the boiler from running into the fire
when there is no stream of air or gas passing up, and for receiving the stream
of smoke, gas, vapour and other products of combustion, and deflecting it down
around the pipe into the water, as shewn by the arrows; w, the seat of the cap
valve; a, a rod for guiding the cap valve, the rod passing through a guide
near the valve, and through a stuffing box in the top of the boiler; y, the safety
valve, the outlet from the safety valve; 1, the main steam pipe leading to
the engine; 2, a valve to cut off the communication with the engine while
any alteration in the state of the boiler may be required; 3, a pipe leading
from a forcing pump for the supplying of water to the boiler, and projecting it
on the top of the cap valve to prevent its becoming too hot; 4, a glass tube
and elbow pipes, leading into the boiler for shewing the height of the water;
5, 51, fire bars lying singly side by side upon a ring rivetted within the furnace,

page_text: just above the ash-pit; about one third of those bars at and near the middle of
the grating, having a loop 5' projecting downwards from the middle of the bar,
into which loop the end of an iron rod may be thrust, forming a temporary
handle by which the bar may be lifted up, and taken out through the ash-pit
as soon as the pressure is removed from the furnace and while under great
heat; 6, the ash-pit; 7, a sliding door, with rack, pinions, slide box and
cover, formed like the sliders, boxes, and covers of the large flue, but placed
vertically to close the ash-pit while pressure is employed within; 8, a ring
between the boiler and furnace to afford a firm support for the bolting on of
the flanch of the slide box 7; 9, a cock to draw off the water and light sedi-
ment from the boiler; 10, an arm-hole and cover to allow access to the inside for
putting in the bolts through the ring 8, and for scraping out any heavy sediment
that will not easily pass out with the water through the cock 9; 11, an air
pipe supplied with air from a blowing machine of any ordinary construction, and
delivering a current of air into the ash-pit; 12, a branch of the air pipe
delivering a portion of the air into the furnace above the fire to aid in the more
perfect combustion of the fuel; 13, two throttle valves and handles to regulate
the proportion of air to be forced in under and above fire; 14, two plates of
glass secured by rings bolted on the ends of two pipes, to allow of inspection
into the furnace and into the ash-pit; 15, a stuffing box to allow of the expan-
sion and contraction of the boiler without straining the joints of the air pipe;
16, two rings between the boiler and the furnace through which the flanches
of the air pipe are bolted; 17, a man-hole for access to the inside of the boiler,
and door with screw clamps to hold it in its place; 18, an arm-hole through
which the bolts may be passed for fastening down the upper part of the flue
upon the top of the boiler; the man-hole and the arm-holes are made oval,
as is commonly done, in order that the doors may be passed through and be
fastened to the inside, so that the pressure may assist in making the joints
tight; 19, the rod or handle passed through the loop 5¹; 20, a scraper
revolving on a bent handle, for clearing away of ashes or clinkers from the
fire bars after one third of the bars about the middle are removed; 21, the
bent handle upon which the curved scraper 20 revolves; a scraper thus
formed may be easily inserted through the ash-pit door, and be used to scrape
away any ashes and clinkers which may be found on the remaining part of the
grating, and thus the labor of removing and replacing two thirds of the bars
may be spared. The other parts, such as the flanches, bolts, and nuts, need not
be referred to, because they commonly occur in steam engine boilers, and they
are obvious on inspection of the Drawings. Since this boiler cannot be cleared.
from ashes and clinkers except when relieved from pressure, it will be necessary

page_text: to employ two or more such boilers to every steam engine which is to be worked
continuously, so that one may be cleared from ashes and clinkers while the
other, or others are supplying. power to the engine. If it should be required
in a particular locality to have a tall chimney, a door must be made in the
side of it a little above the upper slider, through which door the fuel may be
passed into the fuel chamber. In proceeding to work an uncondensing steam
engine with this boiler, I commence with the fire bars in their places, the ash-
pit door open, the throttle valves in the air pipe shut, the cap valve shut, the
two flue sliders open, and the boiler filled with water up to the level shewn
at 22. I then throw a shovel full or more of live coals through the flue
on to the grate, and on the live coals some fuel, which I continue to
add and to spread over the bars by a hooked poker acting upwards through
the interstices between the bars until a strong fire is produced and steam
raised, the air being supplied through the ash-pit, and the smoke escaping
up the chimney. In this state the steam engine is set to work, and simul-
taneously therewith the blowing machine is put in motion, the throttle valves
opened, the lower slide valve in the flue shut, and the ash-pit door shut. The
force of the smoke and other products of combustion will then lift the cap
valve, which will receive the current and deflect it down into the water, to
which the products will impart a portion of their heat and increase the quantity
of steam, while the gases and incondensible vapours will ascend and pass with
the. steam into the cylinder and help to, work the engine. When the fire
requires replenishing the chamber g¹ must be filled with fuel, then the upper
slider must be shut, afterwards the air-cock t shut, and the stop-cock s opened,
allowing the pipe to convey a portion of steam and gas into the chamber,
until the pressure in the chamber is equal to that in the boiler. The lower
slider being then withdrawn, the fuel will fall on the fire and replenish it, and
this operation is to be repeated as often as necessary until the accumulation of
ashes or clinkers or both shall prevent the fire from burning as strongly as is
desired, when the valve 2 must be shut, leaving the engine to be worked by
the other boiler or boilers. The blowing machine must then be stopped, the
safety valve opened, as also the stop-cock and the air-cock s; that the pressure
may. be soon reduced in, the boiler, and the ash-pit door raised, a few of the fire
bars near the middle taken out, the remaining parts of the grate cleared and
the bar's replaced, after which the fire may be made on the grate, and the pro-
ceedings above detailed repeated. The Drawings being now explained, and
the mode of working described, I can easily distinguish the parts which I
claim from the parts in previous use, and which are here merely given. for
illustration.
"

page_text: I therefore declare that I lay no claim to the Invention of forcing air in
under and over the fire, nor of any form of blowing machine, or of pipes used
in transmitting the air; and I lay no claim to the delivery of the products
of combustion through long narrow and crooked pipes into the water near the
bottom of the boiler, and heretofore used; and I lay no claim to the mode of
constructing the steam pipe, steam valve, safety valve, inspection tube, or cold
water feeding pipe, nor to any particular mode of putting the boiler together.
But I claim the use of one short, wide, and straight pipe of communication
surmounted by a cap valve, through which pipe I deliver the products of
combustion into the boiler, a little way below the surface of the water. I
claim the use of two sliding shutters in the flue when in combination with
other of the improvements in this class of engine herein described, whereby
I am enabled to feed the fire while the engine is at, work. I claim the loop
projecting downwards from the middle of the fire bars, whereby the bar may
be taken out of the furnace while hot. I claim the use of a tube of communi-
cation from the furnace to the fuel chamber in the flue. I claim the use of a
stop-cock and air-cock in the said tube. And, finally, I claim the use of two
glass windows in the air pipe to allow of inspection into the furnace and into
the ash-pit.
In witness whereof, I, the said John Isaac Hawkins, have hereunto set
my hand and seal, this Fourteenth day of August, in the year of our
Lord One thousand eight hundred and thirty-seven
JOHN ISAAC (L.S.) HAWKINS.
AND BE IT REMEMBERED, that on the Fourteenth day of August, in the
year of our Lord 1837, the aforesaid John Isaac Hawkins came before our said
Lady the Queen in Her Chancery, and acknowledged the Specification afore-
said, 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-seven.