IMPROVEMENTS IN STEAM BOILERS.
Year: 1873

page_text: LETTERS PATENT to James Howard, of Bedford, in the County of
Bedford, Agricultural Engineer; and Edward Tenney Bousfield, of
the same Place, Engineer, for the Invention of "IMPROVEMENTS IN
STEAM BOILERS.".
PROVISIONAL SPECIFICATION left by the said James Howard and
Edward Tenney Bousfield at the Office of the Commissioners of
Patents, with their Petition, on the 3rd April 1873.
We, JAMES HOWARD, of Bedford, in the County of Bedford,
Agricultural Engineer, and EDWARD TENNEY BOUSFIELD, of the same
Place, Engineer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN STEAM BOILERS," to be as follows:-
The object of our present Invention is to improve the class of tubular
steam boilers for which we obtained at various times Letters • Patent,
among which are the following, namely, one bearing date November
14th, 1868, No. 3468; and another December 30th, 1869, No. 3770.
$

page_text: These boilers may be described as composed of sections or groups of
tubes consisting of horizontal or nearly horizontal tubes with one or
more vertical tubes connecting them together and two or more of such
sections being themselves connected together by common water and
steam ways.
Hitherto we have so constructed these boilers that when set the flame
and heated gases have acted upon the outside surfaces only of such
tubes.
By our present improvements we obtain an increased heating surface
within a given area of fire chamber by passing the flame and heated
gases through as well as over and around any desired number of the
horizontal tubes of each section. Supposing each section to be composed
of four tubes connected together as heretofore practised we shall in
general construct the lowest and the uppermost tubes as heretofore, using
them respectively as water and steam tubes.. The intermediate tubes we
propose to fit with groups of fire-tubes which will run from end to end
thereof. The tubes containing these groups of fire-tubes will be arranged
so as to leave a free space between their ends and the back and front of
the fire chamber for the flame and heated gases to enter and pass out of
the open ends of the fire-tubes in their course from the fire-place to the
escape flue of the fire chamber. The sections we propose to arrange as
heretofore to obtain the serpentine course for the flame and heated gases
externally of the tubes. Thus one or more of the tubes of each section
will be heated both externally and internally, and a rapid generation of
steam will result. The circulation of the water in the boiler will also
be quickened.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said James. Howard and Edward Tenney Bousfield
in the Great Seal Patent Office on the 3rd October 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JAMES 3
HOWARD, of Bedford, in the County of Bedford, Agricultural Engineer,.
and EDWARD TENNEY BOUSFIELD, of the same Place, Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her.
Letters Patent, bearing date the Third day of April, in the year of our 3
:

page_text: Lord One thousand eight hundred and seventy-three, in the thirty-sixth
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto us, the said James Howard and Edward Tenney Bousfield,
Her special licence that we, the said James Howard and Edward
Tenney Bousfield, our
our executors, administrators, and assigns, or
such others as we, the said James Howard and Edward Tenney
Bousfield, our executors, administrators, 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,
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 TUBULAR STEAM BOILERS," upon the condition (amongst
others) that we, the said James Howard and Edward Tenney Bous-
field, our executors or administrators, by an instrument in writing under
our, or their, or one of their hands and 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 James Howard, on behalf of
myself and of the said Edward Tenney Bousfield do hereby declare the
nature of our 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 had to the Drawings hereunto
annexed and to the letters and figures marked thereon (that is to
say) :—
The object of our present Invention is to improve the class of tubular
steam boilers for which we obtained at various times Letters Patent,
among which are the following, viz., one bearing date November Four-
teenth, One thousand eight hundred and sixty-eight, No. 3468, and
another December Thirtieth, One thousand eight hundred and sixty-nine,
No. 3770.
These boilers may be described as composed of sections or groups of
tubes consisting of horizontal or nearly horizontal tubes with one or
more vertical tubes connecting them together, and two or more of such
sections being themselves connected together by common water and
steam ways.
Hitherto we have so constructed these boilers that when set the flame

page_text: and heated gases have acted upon the outside surfaces only of such
tubes.
By our present improvements we obtain an increased heating surface
within a given area of fire-chamber by passing the flame and heated
gases through as well as over and around any desired number of the
horizontal tubes of each section.
In the accompanying Drawings we have shown our Invention as
applied to several arrangements of tubular boilers, which arrangements
are severally devised for special requirements.
In Sheet I., Fig. 1 shews in front elevation, partly in section, and
Fig. 2 in longitudinal sectional elevation a boiler so arranged that any
one tube of a section may be removed without withdrawing the whole
section from the fire chamber. This arrangement of boiler is moreover
adapted for both marine and land purposes.
The boiler consists of three sections, each section of which is composed
of four tubes A, B, B', and C, connected together by flanged vertical pipes
near their opposite ends, and enclosed within a metal casing forming
the fire chamber. The bottom tube A is fitted with a tubular fire
chamber A¹, provided with fire-bars a and a fire-brick bridge a¹; the
tube A is fitted at its front end with a fire-door to allow of access to the
grate. The tube A forms a water space around the tube A', and the
upper and lower parts of this water space may be connected together, if
thought desirable, by vertical or diagonal water ways, as shewn at a²;
a man-hole a³ is provided to give access to the interior of the tube A.
This description applies alike to all the bottom tubes of the sections.
The intermediate tubes B, B', of all the sections are cach fitted with
groups of fire-tubes b, in the manner hereafter described, which tubes
run from end to end thereof. The tubes B, B', it will be seen are in this
example made of the same length as the tubes A and C, but it is in all
cases necessary to provide a free space between their ends and the back
and front of the fire chamber to allow of the flame and heated gases
entering and passing out at the open ends of the fire-tubes 6; to this
end extensions of the fire chamber are made, as at D, D¹, D². The
extension D is lined with fire-clay to protect the metal casing from the
destructive action of the fire which is at its fiercest at this part; a man-
hole d is provided in the extension D for giving access thereto and to
the rear end of the tube B; and the extensions D' and D² are provided

page_text: with hinged doors d' and d respectively for giving access to the opposite
ends of the tubes B, B¹. The tubes C are connected together by the
transverse compound coupling pipe E; and the steam is led off from
these tubes by the steam pipe F; the feed water is admitted by a pipe G
to the bottom tube of the sections; H is the chimney for carrying off
the gases of combustion.
By reference to Fig. 2. it will be seen that when it is desired to remove
any one of the tubes of the sections it will only be necessary to withdraw
the bolts from the flanged necks of that tube and the tube may then be
drawn out endwise from the firc-chamber.
. The manner of fitting the tubes B, B', with fire-tubes is illustrated at
Figures 3, 4, 5, and 6, Sheet I. Fig. 3 is a longitudinal section, on an
enlarged scale, of a tube fitted according to our Invention; Fig. 4 is an
end view and Fig. 5 is a cross section of the same. bare the fire-tubes,
supported at one end by a tube plate 6', and at their other end to a tube
plate 6. Fitted to one end of the tube B is a metal ring b³, which forms
à coned seat for the tube plate b¹; the two tube plates are connected
together by being rivetted to strut bars 6. The tube plate 62 is made
somewhat larger in diameter than the barrel of the tube B, and a flange
is rivetted to this tube to enable the tube plate 62 to be connected there-
with by bolts and nuts 6*. This arrangement allows of the withdrawal
of the fire-tubes from the enveloping tube B for repair or renewal by
simply removing the bolts at the front end of the enveloping tube, and
there being no bolts at the rear end of that tube to burn away where
the fire is fiercest the tube fittings will be as little liable to injury as
those of an ordinary locomotive boiler.
i
Instead of making the struts of flat bars rivetted to the plates, as
sliewn at Fig. 5, round rods may be used, as at Fig. 6, the same being
secured to the tube plates by being screwed therein, or tapped and fitted
with clamping nuts.
At Figures 7 and 8 is shewn another arrangement of boiler with our
improvements applied thereto, Fig. 7 being a longitudinal section of a
boiler set in brickwork, and Fig. 8 is a front elevation of the same,
partly in section. In this example the intermediate tubes B, B¹, are
made shorter than the tubes A, C, and in rear of them the tubes A and
Care connected together by means of a vertical tube D. The water
space of the several tubes A, B, B, and C, are connected together. by

page_text: means of the short tubes E. The sections are connected together
through the tubes D by means of the transverse feed water pipe F, and
the tubes C are all connected together by the steam pipe G. The
flame and heated gases in passing from the fire-place H, which extends
under the whole of the sections, will circulate around the lower tubes A
and pass to the rear end of the tubes B, where they will be caused to
bend round and enter the fire-tubes 6 by reason of their forward
progress being stopped by the vertical tubes D which abut against each
other and close the end of the fire-place, and by the deflecting fire-
plate I, which extends from side to side of the fire chamber. The heated
gases of combustion on making their exit from the fire-tubes 6 will be
turned back by the front plate of the boiler and by a deflecting plate I¹,
and on again reaching the tubes D they will be caused to return to the
front of the fire chamber through the fire-tubes 6 of the tube B¹, a
deflecting plate I² being provided to ensure this result. The heated
gases on leaving these fire-tubes will circulate around the tubes C of the
several sections and pass off by the flue K to the chimney. By this
arrangement, as well as by that described with reference to Figures 1 and
2, the intermediate tube will be heated both externally and internally
and a rapid generation of steam as well as a quickened circulation of
the water will ensue.
Figures 9 and 10, Sheet II., shew our Invention enbodied in a form of
_sectional boiler, which is specially adapted for marine purposes. In this
example as in the one first described the fire-grates are situate in the
bottom tubes A of the sections. But instead of the fire chambers
extending to the end of the tubes they in this example take a bend
upwards to a flue into which the rear ends of the intermediate tubes B
project. It will be seen that in this boiler there is but one row of tubes
B fitted with fire-tubes, and that these tubes although terminating in
front in a vertical plane with the other tubes, as in Fig. 2, are
considerably shorter than the tubes A and C, which tubes severally
terminate by a junction with the vertical tubes D.
There are two rows of tubes C, the upper row of which will serve
as steam chambers, and the tubes are all connected together near their
front ends by short necks E. An extension of the fire chamber at
F provides the means for the return back of the flames and heated gases
to the back of the boiler on leaving the internal fire-tubes of the
enveloping tubes B.

page_text: Figures 11 and 12, Sheet III., shew a modification of the sectional
marine boiler. In this example the fire-chamber A¹ contained in the
tubes A are connected by pipes a with a combustion chamber D situate
at the rear of the boiler and surrounded by a water jacket D'. The
fire-tubes 6 of the tubes B extend beyond their enveloping tubes and
pass through the water jacket to the combustion chamber D. In other
respects this boiler is substantially like that last described.
A further modification of a sectional marine boiler with our Invention
applied thereto is shewn in Sheet III., at Figures 13, 14, and 15,
Fig. 13 being a longitudinal section, Fig. 14 a side view with the
casing removed, and Fig. 15 a sectional plan view. The chief
peculiarity of this boiler as contrasted with the others is the application
thereto of a serpentine arrangement of feed water pipes placed at either
side of the boiler. .
Another change consists in making the tubes A of the inner sections
of about half the length of the others and utilizing the space thus
obtained as a fire-place as at A¹. Of the tubes B containing the fire
tubes, there is but one row, and they are contracted in length to allow of
the flame and heated gases circulating through them without providing
an extension of the fire chamber for that purpose. The tubes A, A*,
and C connect at their rear ends with the upright tubes D, and all the
horizontal tubes are connected together by short necks E. F is the
feed water pipe by which all the sections are connected together at
bottom;
and G is a transverse steam pipe by which all the sections are
connected together at top; H, H, are two walls of serpentine pipes
placed externally of the group of sections, and serving to heat the water
before it is supplied to the feed pipe. The water enters this system of
pipes from their connection with the pipe I, and passing upwards to
near the top of the fire chamber it makes its exit by pipes I¹ in a more
or less heated state to the feed water pipe F which distributes the water
to the several sections.
Having now set forth the nature of our Invention of "Improvements
in Tubular Steam Boilers," and explained the manner of carrying the
same into effect, we wish it to be understood that under the above in
part recited Letters Patent we claim,—
First. Obtaining an increased heating surface within a given area in

page_text: Secondly. The mode of fitting the fire tubes within the water tubes,
as described with reference to Figures 3, 4, 5, and 6 of the Drawings.
In witness whereof, I, the said James Howard, have hereunto set
my hand and seal, 'the Third day of October, in the year of our
Lord One thousand eight hundred and seventy-three.