IMPROVEMENTS IN STEAM BOILERS OR GENERATORS AND IN THE PREVENTION OR COMBUSTION OF SMOKE
Year: 1859

page_text: LETTERS PATENT to Thomas Hunt, of Crewe, in the County of Chester,
Engineer, for the Invention of "IMPROVEMENTS IN STEAM BOILERS OR
GENERATORS AND IN THE PREVENTION OR COMBUSTION OF SMOKE."
Sealed the 19th April 1859, and dated the 14th February 1859.
PROVISIONAL SPECIFICATION left by the said Thomas Hunt at the
Office of the Commissioners of Patents, with his Petition, on the
14th February 1859.
I, THOMAS HUNT, of Crewe, in the County of Chester, Engineer, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN STEAM BOILERS
OR GENERATORS, AND IN THE PREVENTION OR COMBUSTION OF SMOKE," to be as
follows:-
This Invention relates to certain improvements in the fire boxes and flues
of steam boilers or generators, whereby the heat from the generator is more
rapidly absorbed on its passage to the chimney, and a consequent economy in
the production of steam is obtained, and coal or other similar fuel may be
advantageously burnt in the furnaces of such boilers, whilst the smoke there-
from is prevented or consumed. These improvements consist,―
Firstly, in the application and use of transverse partitions having one or
more openings made through each, but so arranged that the openings in one
partition are not exactly opposite to those of the next partition in front of it;
the whole being placed in the barrel or circular portion of the boiler of a

page_text: locomotive engine, or in that portion of a multitubular boiler usually occupied
by the tubes, and in a circular or Cornish boiler with one or more flues
through. I propose to commence the partitions at the bridge end of the flue,
and extend them along the entire or a portion of the length of the flue or
flues.
Secondly, in the combination of the above-described transverse partitions
with tubes, the latter being fixed at the end of the boiler or flues or transverse
partitions next the chimney...
Thirdly, in arranging the transverse partitions in boilers having two or
more furnaces or flues in such manner that they may be common to both, or
having separate partitions to each as may be deemed necessary.
Fourthly, in the constructing the fire box of multitubular or locomotive
boilers with a water space or projection attached to the tube plate and to the
crown plate, which projects a portion of the distance towards the opposite sido
of the fire box, by which the direct current of the gases is diverted from the
entrance to the transverse partitions or flues and thrown towards the fire door
plate, through which or the side plates I admit atmospheric air, so as to
ensure the prevention or combustion of smoke.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Thomas Hunt in the Great Seal Patent Office on the
13th August 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
HUNT, of Crewe, in the Country of Chester, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fourteenth day of February, in the year of our
Lord One thousand eight hundred and fifty-nine, in the twenty-second year of
Her reign, did, for. Herself, Her heirs and successors, give and grant unto me,
the said Thomas Hunt, Her special license that I, the said Thomas. Hunt,
my executors, administrators, and assigns, or such others as I, the said
Thomas Hunt, my executors, administrators, or 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, use,
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 OR GENERATORS, AND IN THE PREVENTION OR. COMBUSTION.OF
SMOKE," upon the condition (amongst others) that I, the said Thomas Hunt,

page_text: by an instrument in writing under my hand and seal, 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 Thomas Hunt, do hereby declare
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement, reference being to the accompanying Drawings, and to the letters
and figures marked thereon, that is to say:-
My said Invention relates to certain improvements in the fire boxes and
flues of steam boilers or generators, whereby the heat from the generator is
more rapidly absorbed on its passage to the chimney, and a consequent
economy in the production of steam is obtained, and coal or other similar
fuel may be advantageously burnt in the furnaces of such boilers, whilst the
smoke therefrom is prevented or consumed. These improvements consist,-
Firstly; in the application and use of transverse flue spaces or chambers
having one or more openings made through each, but so arranged that the
openings in one chamber are not exactly opposite to those of the next
chamber, the whole being placed in the barrel or circular portion of the boiler
of a locomotive engine, or in that portion of a multitubular boiler usually
occupied by the tubes and flucs. In a circular or Cornish or marine boiler
with one or more flues through, I propose to commence the partitions at the
bridge end of the flue, and extend them along the entire or a portion of the
length of the flue or flues.
Secondly, in the combination of the above-described transverse chambers
with tubes, the latter being fixed at the end of the boiler or flues or transverse
chambers next the chimney.
Third, in arranging the transverse flue spaces or chambers in boilers having
two or more furnaces or flues in such manner that one set of transverse
chambers inay be used in common to all the furnaces, or have a separate
series of chambers to each, as may be deemed necessary.
Fourth, in the constructing the fire boxes of multitubular or locomotive
boilers with a water space or midfeather attached to the tube plate and to the
crown plate, such water space projecting a portion of the distance towards the
opposite side of the fire box, by which the direct current of the gases is
diverted from the entrance to the transverse partitions or flues and thrown
towards the fire door plate, through which or the side plates I admit
atmospheric air, so as to ensure the prevention or combustion of smoke.

page_text: And in order that my said Invention may be fully understood, I shall now
proceed more particularly to describe the same, and for that purpose I shall
refer to the several Figures on the Sheets of Drawings hereunto annexed, the
same letters of reference indicating corresponding parts throughout all the
corresponding figures.
. Figure 1' on 'Sheet 1 of my Drawings represents a longitudinal vertical
section of a locomotive boiler constructed and arranged according to my
Invention; Figure 2 is a corresponding sectional plan of the same; Figure 3
is a front elevation of the fire box end of the boiler, shewing my peculiar
fire door; and Figure 4 is a transverse section taken along the line 3-4, in
the barrel of the boiler.
A, A, represents the outer shell of the boiler which may be of the ordinary
construction, but in lieu of having long tubes extending from the fire box to
the smoke box, I place inside the barrel of the boiler a series of transverse
partitions or fluc spaces B, B, with water spaces C, C, between them. These
flue spaces consist of semicircular or other suitably shaped chambers filling the
interior of the barrel of the boiler below the water wheel, but disconnected
therefrom, so as to admit of their withdrawal in a body from the boiler when
required for repairs. Each flue space is connected to its neighbour by a
passage D, but these passages are arranged so as to enter and leave the
several flue spaces at different points, by which means no two passages are
opposite to or in direct communication with each other, and hence the flame
and products of combustion must necessarily follow a circuitous or zig-zag
course, as shewn clearly in the sectional plan, Figure 2. The first of the
series of flue spaces is connected with one side of the fire box by the passage
E, and the last of the series opens into the transverse chamber F, which
communicates by a number of short tubes G with the smoke box H. A man-
bole I is formed in the bottom of the transverse chamber F for the facility of
cleaning it and of conducting repairs. This series of short tubes may, if
found desirable, be dispensed with, and the last of the series of flue spaces or
transverse chambers will then open direct into the smoke box by a passage D.
In some cases I insert into the lower portions of one or more of the several
flue spaces or chambers B, a series of tubes b, b, which pass through the shell
of the boiler and serve to admit a sufficient supply of fresh air to effect the
perfect combustion of the unconsumed products of combustion arising from
the fuel. In order the more readily to collect the air and direct and regulate
its flow into and through these tubes, I propose to attach to the under side of
the barrel of the boiler a series of boxes c fitted with valves or regulators &,
which are under the immediate control of the engineer. By this means tho

page_text: supply of air to the flue spaces B may be regulated and adjusted with the
greatest nicety. J represents a midfeather or water space connected to
the tube plate and crown plate of the fire box. This water space extends at
its upper end considerably towards the front of the fire box, but it gradually
tapers downwards towards the fire bars, as is clearly shewn in Figure 1. A
slight lateral inclination is also imparted to this water space towards that side
of the fire box containing the entrance or passage E into the flue spaces, as.
will be seen on referring to the plan, Figure 2. The fire door K is of a
peculiar construction, and is placed eccentrically in the fire, box, so as to be,
opposite to the edge of the laterally inclined midfeather. This fire door is of.
an oval shape with the longer axis placed vertically, as shewn in Figure 3; it
is made to open in the centre only, having a feed hole L of, say, eleven inches
high by thirteen inches wide, more or less; the parts of the oval M, M, above
and below this doorway are composed of perforated metal plates, and the
actual door itself is also perforated, whereby a free supply of divided currents -
or jets of air to the furnace is obtained.
Figure 1 on Sheet 2 of my Drawings represents a longitudinal vertical
section of a marine boiler provided with several series of transverse divisions
or flue spaces, and Figure 2 is a transverse vertical section of the same taken.
at three different points.
A, A, are the boiler furnaces, each one of which opens into a separate.
series of transverse flue spaces or chambers B, disposed inside the outer shell
of the boiler in such a manner as to leave a water space C, C, between each
chamber. The several chambers in each series are connecteil by passages
D, D, arranged so that no two consecutive passages come opposite cach otlier,.
by which means the flame and products of combination are caused to make a
zig-zig course, and to traverse the length of each individual flue space or
chamber, as will be evident on referring to the Drawing. The passage or
openings E, E, connect the first or front chamber of each series with its-
respective furnace, the lower portion of such passage or opening forming the
fire bridge. The last of each of the lower series of chambers B opens into the.
lower portion of the transverse chamber F, which may, if required, be common
to all the chambers, or otherwise. The upper portion of this transverse chamber
communicates with the several series of transverse fluc spaces or chambers
B', B', which are placed above and rest upon the lower series B. The upper
series of chambers B₁ are of precisely the same construction and arrangement
as the lower ones, and finally terminate in the uptake G leading to the
chimney, the uptake being common to all the furnaces and series of fluc
spaces. In Figure 2 the left-hand furnace is represented in transverse section

page_text: taken along the line 1-2, in Figure 1; the centre compartment is represented
in section taken along the line 3-4, and the right-hand series are shewn in
section taken along the line 5-6. The arrows in these two Figures indicate the
course of the flame and gases through the several series of chambers till they
finally reach the chimney. As in the locomotive boiler herein-before described,
these chambers B and B' are fitted loosely within the boiler shell, and are
easily removed in a body when requisite.
Figure 3 on Sheet 2 of my Drawings represents a sectional plan of a
cylindrical or Cornish boiler provided with my transverse partitions or flue
spaces, and Figure 4 is a transverse section of the same taken through the
furnaces. A, A, are the furnaces, of which there are two, both opening by the
passages E, E, into the first of the series of flue spaces or chambers B, B; a
central passage E' connects the front chamber with the next one, and tho
remainder of the series communicate with each other on opposite sides by the
several passages D, the last of the series opening by the passage D' into
the main flue or chimney. C, C, are water spaces. In all cases the chambers
B are made of such a height that the level of the water in the boiler will
always be a few inches above the tops of the chambers. If found desirable,
one or more of the chambers B in the marine as well as in the Cornish boiler
last referred to, may be provided with tubes or air pipes, as shewn at b, b,
disposed at the bottom and sides of those chambers where applicable. It is
obvious also that in the arrangement of the marine boiler the several furnaces
may open into one series of wide chambers B common to the three furnaces,
as shewn in the Cornish boiler, Figures 3 and 4, in place of each furnace
having a separate set of chambers of its own. The upper series of chambers
B (Figures 1 and 2) may also be combined into one series of wide chambers,
each provided with one or more passages D' for connecting them together.
It is also obvious that in the Cornish boiler above referred to, one furnace
may be used instead of two with the arrangement of transverse chambers, as
described. Any number of these chambers may be combined or not with the
ordinary boiler tubes or tubular draught thoroughfares if desired.
Having now described and particularly ascertained the nature of my said
Invention, and the manner in which the same is or may be used or carried
into effect, I would observe, in conclusion, that what I consider to be novel
and original, and therefore claim as the Invention secured to me by the
herein-before in part recited Letters Patent, is,-
First, the general internal construction and arrangement of steam boilers of
locomotive, marine, and stationary engines, as herein-before described.
Second, the arranging of one or more series of transverse flue spaces or

page_text: chambers individually connected by suitably disposed passages within the
outer shell of a steam boiler or generator, as herein-before described.
Third, the combination of tubes or tubular draught thoroughfares with
transverse flue spaces or chambers, as herein-before described.
Fourth, the combination of a series of transverse flue spaces or chambers
with more than one furnace in such a manner that the single series of
flue spaces or chambers shall be common to all the furnaces, as herein-before
described.
Fifth, constructing the fire boxes of locomotive or multitubular boilers with
a water space or midfeather attached solely to the tube plate and crown plate
of the fire box, and otherwise arranged in the manner herein-before described.
In witness whereof, I, the said Thomas Hunt, have hereunto set my
hand and seal, this Sixth day of August One thousand eight hundred
and fifty-nine.
THOS. HUNT. (L.S.)
THOS. HUNT. (L.S.)