IMPROVEMENTS IN STEAM BOILERS
Year: 1873

page_text: LETTERS PATENT to John Imray, of No. 20, Southampton Buildings,
Chancery Lanc, in the County of Middlesex, for the Invention of
"IMPROVEMENTS IN STEAM BOILERS."-A communication from abroad
by Gustave Quimbel, of Elbeuf, France, Boiler Maker.
Scaled the 29th April 1873, and dated the 27th January 1873.
PROVISIONAL SPECIFICATION left by the said John Imray at the
Office of the Commissioners of Patents, with his Petition, on the
27th January 1873.
I, JOHN IMRAY, of No. 20, Southampton Buildings, Chancery Lane,
in the County of Middlesex, do hereby declare the nature of this said
Invention for "IMPROVEMENTS IN STEAM BOILERS," to be as follows:-
This Invention relates to a construction and arrangement of steam
boilers and the flues and heating surfaces thereof, so as to secure the
greatest possible cooling of the products of combustion, and thus to
utilize to the greatest extent the heat evolved from the fuel. For this
purpose the main body of the boiler is made of cylindrical form with an

page_text: internal fluc in the manner of a Cornish boiler, but this flue is placed
with its centre so far below that of the boiler itself, and is of such
diameter that if its circumference were continued it would project below
the boiler; the section of the boiler is thus made of crescent form, the
flue being open along its under side. The fire is placed in the front
part of the flue, the fire-bars being level with the edges of the crescent
shaped boiler, and in the back part of the fluc is placed a cylindrical
generator of smaller diameter than the flue, so that an annular space is
left around it, through which the products of combustion pass on their
way backwards. This generator communicates at top by largo ducts
with the body of the boiler, so that steam generated in it can readily
pass upward into the boiler, and the cooler water can descend into it.
On each side of the boiler a fluc is formed in the setting, along which
flucs thic products of combustion after having passed backwards through
the central flue return to the front of the boiler. In each of these side
flues is placed a cylindrical generator communicating by large ducts
on the upper parts of their sides with the body of the boiler, which
generators are heated by the products of combustion passing along them
towards the front of the boiler. Beneath the boiler the flue is carried
backwards and forwards several times in zig-zag directions, each of these
successive channels being alternately to the side of and beneath tho
level of the former. In cach of these channels is placed a tube com-
municating each alternately at its front and back ends with the tubes
above and below it. Into the lowest of these tubes, which is situated in
the last and coolest channel of the fluc, the feed water is introduced, and
it has to pass along the whole length of each successive tube, and from
cach to the next above it, and finally through a tube placed in the ash-
pit, which in its tarn communicates with the generators on either side
of the boiler. The feed water is thus gradually heated up on its way
to the boiler, and the products of combustion are gradually cooled in
their course along the successive channels of the fluc.
In order to utilize any residuary heat left in the products of com-
bustion, after they have left the last of the channels described above,
they are led on their way to the chimney along a zig-zag pipe of thin
sheet metal arranged in a chamber under the boiler in the spaco
unoccupied by the above-mentioned flue channels. The air for sup
porting the combustion of the boiler fire is admitted at the bottom of
this chamber and issues from its top into the ash-pit, warmod by passing

page_text: the zig-zag flue pipe, so that the boiler fire is thus supplied with warmed
or licated air, while the products of combustion are cooled so as to carry
with them little waste heat.
In starting a boiler constructed and arranged as above described the
products of combustion instead of being made to travel in the tortuous
course of the zig-zag flue channels and pipes can be permitted to escape
directly to the chimney from the side flues of the boiler. For this
purpose a sliding damper or valve is arranged in a channel com-
municating from these flues to the chimney. This damper or valve
is opened at first starting the working of the boiler, and when the
draught has been established it is closed so as to make the products of
combustion travel along the more tortuous and extended course of the
flue channels and pipes, as described above.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Imray in the Great Seal Patent Office on
the 28th June 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
IMRAY, of No. 20, Southampton Buildings, Chancery Lanc, in the
County of Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-seventh day of January, in
the year of our Lord One thousand cight hundred and seventy-three,
in the thirty-sixth year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto me, the said John Imray, Her special
license that I, the said John Imray, my executors, administrators, and
assigns, or such others as I, the said John Imray, my executors, adminis-
trators, and assigns, should at any time agree with, and no others, from
time to time and at all times thereafter during the term therein expressed,
should and lawfully might make, usc, exercise, and vend, within the
United Kingdom of Great Britain and Ireland, the Channel Islands
and Isle of Man, an Invention for "IMPROVEMENTS IN STEAM BOILERS," a
communication to me from abroad by Gustave Quimbel, of Elbeuf,
France, Boiler Maker, upon the condition (amongst others) that
I, the said John Imray, my executors or administrators, by an in-.
strument in writing under my, or their, or one of their hands and

page_text: seals, should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed, and
cause the same to be filed in the Great Seal Patent Office within
six calendar months next and immediately after the date of the said
Letters Patent.
NOW KNOW YE, that I, the said John Imray, do hereby declare
the nature of the said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by
the following statement thereof, reference being being had to the accom-
panying Sheet of Drawings, and to the figures and letters marked
thereon, that is to say:
-
This Invention relates to a construction and arrangement of steam
boilers, and the flues and heating surfaces thereof, so as to secure the
greatest possible cooling of the products of combustion, and thus to
utilise to the greatest extent the heat evolved from the fuel.
Fig. 1 represents a transverse, and Fig. 2 a longitudinal section of a
boiler and its flues and heating surfaces constructed and arranged
according to this Invention. The main body of the boiler is of cylindrical
form, with an internal flue in the manner of a Cornish boiler, but the
flue is placed with its centre so far below that of the boiler itself, and
is of such diameter that the section of the boiler is made to resemble a
crescent, having the flue open along its under side. The fire-grate B is
placed in the front part of this opening extending in width from point
to point C of the crescent. In the back part of the internal flue, behind
the fire-grate, is placed a cylindrical generator A of smaller diameter
than the fluc, so as to leave an annular space D round it for the passago
backwards of the products of combustion. One or more large ducts A¹
form a communication between the generator A. and the body of the
boiler, so that steam generated in A can readily pass upwards into the
boiler, and cooler water can descend from the boiler into the generator.
Flues E, E, are formed in the setting along cach side of the boiler,
by which flues the products of combustion return from the back end of
the boiler to the front. In each of these side flues is placed a cylindrical
'generator F, F, communicating with the boiler by large ducts F towards
their upper sides. Beneath the boiler the flue is carried backwards and
forwards several times so as to form zig-zag channels II', H*, &c., cach
channel being to the side of and lower than the preceding channel, and
communicating at the one end with the channel, which precedes, and

page_text: at the other end with the chaune), which succeeds it, so that tho
products of combustion have to pass backwards along the channel H',
forwards along H³, and so on successively till they finally pass along
the last of the channels H to a pipe, which will be hereafter described.
In each of the channels H', H³, &c., is placed a tube marked No. 1,
No. 2, &c., and cach of these tubes communicates at the one end with
the tubo next above it, and at the other end with that next below it by
sloping passages or waterways marked G³, G³, &c. The highest of the
tubes No. 1, which is placed in the ash-pit and channel H' forming the
continuation of the ash-pit, communicates by waterways G with the
side generators F, F. The feed water for the boiler being supplied to
the back end of the lowest tube No. 9 has to pass along the successive
tubes in a direction opposite to that in which the products of combustion
pass along the successive channels, and thus becomes gradually heated
on its way to the boiler, while the products of combustion are gradually
cooled in their course along the successive channels of the fluc.
In order to utilise such residuary heat as may be left in the products
of combustion after they have left the last channel H they are led from
that channel on their way to the chimney through a zig-zag pipe K of
thin sheet metal arranged in a chamber under the boiler in the space
unoccupied by the flue channels above described. The air for sup-
porting the combustion of the boiler fire is admitted by a passage Lat
the bottom of this chamber, and issues from its top by a passage M
leading to the ash-pit, being warmed by passing the zig-zag flue pipe K.
The boiler fire is thus supplied with heated air, while the products of
combustion are cooled so as to carry little waste heat with them to the
chimney.
Although, after the chimney draught has been fairly established, the
products of combustion may be made to pass along the tortuous course
above described it is to be understood that in first starting the boiler
they can be conducted directly from the side flucs E or bottom flue H'
of the boiler to the chimney. For this purpose either of these flues
may have a direct passage to the chimney, provided with a valve or
damper, which can be opened when the boiler is started, and closed
after the draught is established.
Having thus described the nature of the said Invention and in what
manner the same is to be performed, as communicated to me by my
foreign correspondent, I claim,-

page_text: First. The combination, so as to form one steam boiler, of a main
boiler body of crescent form with one generator in the central and two
generators in the side flues, and several heating tubes in the fluo
channels, substantially as herein described.
Second. The use of a crescent shaped boiler having its fire in the front [
part, and a generator in the back part of its fluc, substantially as herein
described.
1
Third. The arrangement of the flue channels and heating pipes
therein, so that while the products of combustion pass along the former
in one direction the feed water on its way to the body of the boiler 1
flows along the latter in the opposite direction, substantially as herein
described.
Fourth. The arrangement of a zig-zag flue pipe K in a chamber,
through which passes the air for supplying the boiler fire, whereby
the air is warmed and the residuary heat in the products of combustion ]
is utilised before the latter escapes, substantially as herein described.
In witness whereof, I, the said John Imray, have hereunto set
my hand and seal, this Eighteenth day of June, in the year of
our Lord One thousand eight hundred and seventy-three.