IMPROVEMENTS IN STEAM BOILERS
Year: 1874

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 26th January 1874.
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
boilers for novel arrangements of which we have obtained at various
times Letters Patent. Among these Patents are the following, namely,
one bearing date December 30th 1869, No. 3770, another dated 25th
March 1872, No. 905, and another April 3rd 1873, No. 1237.

page_text: The class of boilers to which our improvements are directed may be
described as composed of sections or groups of tubes placed horizontally
or nearly so with one or more vertical tubes connecting the horizontal
tubes together, any number of such sections being used in combination
according to the amount of steam required to be produced.
By our present improvements we obtain increased efficiency in
working and an economy in the consumption of fuel, and we also secure
facilities for cleaning and for inspection and repairs.
The first part of our Invention relates to the combination of com-
bustion chambers of a novel construction with tube sections, the lower
tube of which is fitted with a furnace tube, and the upper tubes of the
section (one or more) are fitted with nests of flame tubes through which
the heat passes on its way to the chimney.
The lower combustion chamber consists of a cylinder with a closed
end; this cylinder forms a continuation of the furnace tube which fits
into the open end thereof. A similar cylinder constitutes the upper
combustion chamber, of which there may be one or more, and into the
open thereof fits the tube plate of the nest of tubes with which the
upper horizontal tubes of the sections are provided. The combustion
chambers of the section are connected together so as to allow of the
flame and heated gases passing from one chamber to the other, and to
the nests of tubes by means of a short cylindrical neck made fast to the
combustion chambers by rivets or otherwise.
Around and at the back of the combustion chambers a water space is
left between them and the outer shell of the boiler, and to the back
plates of the sections their respective combustion chambers are secured
by stays which serve to retain them in position. These back plates are
also attached by bolts and nuts to the rear ends of their respective
furnace tubes and of the tubes fitted with nests of flame tubes, or the
joint with the tubes and the rear end of the section may be in the plane'
of the axis of the short cylindrical neck before mentioned. The object
of this arrangement is to secure the advantages of withdrawing either
the fire or furnace tube, or the nests of tubes, or the combustion
chambers, and also to obtain a perfect water jacket for those chambers.
It is sometimes desirable to construct the sections of tubes so that the
lower tube may contain a furnace at each end, and also that the upper
tube or tubes of the sections may receive a nest of tubes at each end

page_text: above the furnace.
In such cases the combustion chambers are placed
in the middle of the length of their respective tubes, and the two furnace
tubes and two nests of tubes are jointed into opposite ends of the
cylindrical combustion chambers. This arrangement is well adapted to
secure perfect combustion by alternately firing the furnace at opposite
ends of the section.
Another part of our Invention relates to improvements in the con-
struction of the sections of tubes composing a boiler where the flame
acts only on the external surfaces of the tubes, a type of which sections
is described and illustrated in the Patent granted to us December
30th 1869, No. 3770.
Our improvements consist in a novel method of attaching the con-
nections or heads at each end of the horizontal tubes. Instead of
attaching them by rivets or by conical threaded screws, as described in
former Patents, we now propose to cast these connections on the outside
of the longitudinal tubes, a small ring of wrought iron being first shrunk
on the outside of the tube. This ring is made to project slightly beyond
the end of the casting, and by the well known process of caulking or
setting up a secure water and steam-tight joint is made between the
wrought-iron tube and the cast-iron head.
In order to obtain a more ready access for cleaning the tubes internally
when the closing caps are removed at the ends of the tubes, we substitute
instead of the jointed tie bolt described in the Patent (No. 905/72) before
referred to, or the outside bolts shewn in a more recent Patent, (No. 1237,
of 1873,) a flat bar fitted with a cross bridge in the bottom tube, the ends
of which bridge butt against a shoulder or enter recessos cast in the
tube. This arrangement provides ready access to the bottom tube for
cleaning and raking out the scale, while the other tubes of the section
are only obstructed by the thin edge of the flat bar.
We protect the joints from the action of the flame and afford facilities
for examining them by grooving each side of the head or connecting
pieces to receive (when put together) thin fire-bricks or plates of metal,
which by forming a wall or partition will secure protection for the joints
against the flame and heated gases of the furnace.

page_text: 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 25th July 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JAMES
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 Twenty-sixth day of January, in the
year of our Lord One thousand eight hundred and seventy-four, in
the thirty-seventh year of Her reign, did, for Herself, Her beirs and suc-
cessors, 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 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 STEAM BOILERS," upon the condition (amongst others)
that we, the said James Howard and Edward Tenney Bousfield, 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 we, the said James Howard, and 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 Drawing 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
boilers, for novel arrangements of which we have obtained at various

page_text: times Letters Patent; among these Patents are the following, viz., one
bearing date December Thirtieth One thousand eight hundred and sixty-
nine, No. 3770, another dated Twenty-fifth March, One thousand eight
hundred and seventy-two, No. 905, and another April Third, One
thousand eight hundred and seventy-three, No. 1237.'
The class of boilers to which our improvements are directed may be
described as composed of sections or groups of tubes placed horizontally
or nearly so with one or more vertical tubes connecting the horizontal
tubes together, any number of such sections being used in combination
according to the amount of steam required to be produced.
By our present improvements we obtain increased efficiency in
working and an economy in the consumption of fuel, and we also secure
facilities for cleaning and for inspection and repairs.
The first part of our Invention relates to the combination of com-
bustion chambers of a novel construction with tube sections, the lower
tube of which is fitted with a furnace tube, and the upper tubes of the
section (one or more) are fitted with nests of flame tubes through which
the heat passes on its way to the chimney.
:
In Sheet I. of the accompanying Drawings Fig. 1 shews in front
elevation this improved construction of boiler composed of three sections
or groups of tubes; and Fig. 2 is a section of the same taken in the
line 1, 2, of Fig. 1. Each section is composed of water tubes A, B,
and C connected together by necks D, D, D, and E is a steam tube
running transversely across the boiler and connecting the several sections
together by means of necks F. Within each tube A. is a furnace tube A¹
fitted with fire bars A³, and within each tube B is a nest of tubes B¹
held together by tube plates and fitted centrally therein. A³ is a
cylinder forming a continuation of the tube A¹; this cylinder constitutes
what we term the lower combustion chamber, and it is closed by a
flanged end plate. A similar cylinder B² constitutes the upper com-
bustion chamber, and into the open end thereof fits the tube plate of
the nest of tubes B¹ with which the horizontal tubes B of the sections
are provided. The combustion chambers of the section are connected
together so as to allow of the flame and heated gases passing from one
chamber to the other, and to the nest of tubes by means of a short
cylindrical neck D¹ made fast to the combustion chambers by rivets or

page_text: otherwise. Around and at the back of the combustion chambers a
water space is left between them and the outer shell of the boiler, and
to the back plates of the sections their respective combustion chambers
are secured by stays which serve to retain them in position. These back
plates are also attached by bolts and nuts to the rear ends of their
respective furnace tubes A and B; or the joint with the tubes and the
rear end of the section may be in the plane of the axis of the short
cylindrical neck D', as indicated by the dotted lines in Fig. 2. The
object of this arrangement is to secure the advantages of withdrawing
either the fire or furnace tube, or the nests of tubes, or the combustion
chambers, and also to obtain a perfect water jacket for those chambers.
In front of the tubes B a flue G is provided leading to the chimney, and
opposite the fire tubes B¹ openings are made in this flue to allow of
access to the front ends of the fire tubes. These openings are closed by
hinged doors or covers G¹. The rear tube plates are flanged and fitted
to the combustion chamber B' by a coned joint, after the manner
described in the Specification of our Patent, dated April Third, One
thousand eight hundred and seventy-three, No. 1237, and a similar
arrangement is provided for fitting the other tube plate to the end of the
water tube B. The joints of the furnace tubes A' are similarly con-
structed.
A modification of the above described arrangement is shewn in
Sheet II., where Fig. 3 is a longitudinal sectional elevation of the boiler;
and Fig. 4 is a back elevation of one of the sections. In this arrange-
ment in place of the combustion chambers formed of two cylinders con-
nected together by a neck, we construct an oblong fire-chamber by
means of an end plate H and a band of boiler plate I, which latter we
secure to tubular continuations of the furnace tube and the rear tube
plate, and we complete the connection with these tubular continuations
by means of a flanged plate K shaped to fit the space between them and
the band I. K¹ is a second plate (of corresponding form to the plate K)
which connects the upper and lower tubes A and B with a second band
of boiler plate iron l' constituting a portion of the outer skin of the
boiler. The plate H is connected by stays to the back plate, and these
together form a water space in rear of the fire-chamber. In other
respects this boiler is constructed in a similar manner to that shown in
Sheet I., the like parts in both arrangements being indicated by similar
letters of reference.

page_text: It is sometimes desirable to construct the sections of tubes so that the
lower tube may contain a furnace at each end, and also that the upper
tube or tubes of the sections may receive a nest of tubes at each end
above the furnaces. In such cases the combustion chambers are placed
in the middle of the length of their respective tubes, and the two furnace
tubes and two nests of tubes are jointed into opposite ends of the
cylindrical combustion chambers. This arrangement is shewn in
Sheet III., where Fig. 5 is a longitudinal vertical section of the boiler;
and Fig. 6 is a partial transverse section of the same taken through the
line 1, 2, of Fig. 5. In these Figures the same letters of reference are
used as in Sheet I. for the like parts. The description therefore of the
first arrangement will in great part apply to this double furnace boiler.
The combustion chambers A³, B³, however are in this example open at
both sides to allow of the flames from the two fires passing through
them and turning in opposite directions to the nests of tubes B¹, B¹.
The outer ends of these two sets of fire tubes are enclosed in flues G¹,
and these flues are led upwards so as to meet in one common flue G
leading to the chimney. By this duplicate arrangement a most
economical combustion of the fuel may be ensured, the furnaces at the
opposite ends of the sections being fired alternately.
Another part of our Invention relates to improvements in the con-
struction of the sections of tubes composing a boiler where the frame
acts only on the external surfaces of the tubes, a type of which sections
is described and illustrated in the Patent granted to us December
Thirtieth, One thousand eight hundred and sixty-nine, No. 3770.
.
Our improvements consist in a novel method of attaching the con-
nections or heads at each end of the horizontal tubes. Instead of
attaching them by rivets or by conical threaded screws, as described in
former Patents, we now propose to cast these connections on the outside
of the longitudinal tubes, a small ring of wrought iron being first shrunk
on the outside of the tube. This improvement is illustrated at Fig. 7,
Sheet IV., which shows in vertical section a group of three tubes with
their attachments. In this Figure a, a, are the horizontal tubes; and b
are the rings shrunk thereon. Rivet holes are bored through each ring
and tube, and they are then ready to have the heads c cast upon them.
It should be remarked that the rings 6 are made to project 'slightly
beyond the ends of their respective castings; this is to allow of the well

page_text: known process of caulking or setting up being applied to the rings to
form a secure water and steam-tight joint between the wrought-iron
tube and the cast-iron head.
In order to obtain a more ready access for cleaning the tubes
internally when the closing caps are removed at the ends of the tubes,
we substitute instead of the jointed tie bolt described in the Patent
(No. 905/72), before referred to, or the outside bolts shewn in a more
recent Patent (No. 1237/7), a flat bar fitted with a cross bridge in the
bottom tube head, the ends of which bridge butt against shoulders on or
enter recesses cast in the tube head. This arrangement is shewn in trans-
verse vertical section at Fig. 8, and in partial longitudinal section at Fig. 9,
where c, c¹, are the heads to be coupled together; d is the flat bar and e
the cross bridge bearing upon shoulders in the bottom tube head e¹.
The flat bar d is screwed at its upper end and it passes through the head
of the uppermost tube to receive a nut from which it is suspended.
In the lower end of the bar da slot is made to receive the cross bridge e.
When the heads are fitted together the nut fis turned, until by the aid
of the cross bridge the joints of the heads are drawn tight.
As a simple and efficient mode of making these joints we prefer a
modification of the plan described in the Patent granted to us March:
Twenty-fifth, One thousand eight hundred and seventy-two, No. 905,
illustrated at Figures (4, 5, and 6. Instead of the spherical seating in
the cast-iron heads we cone the coupling edges of the castings c, c, and
insert them in hollow double coned expansion rings g. As therefore the
tie bar d is tightened up the socket joints will be firmly secured, and the
stout wrought-iron expansion ring 9 will prevent the splitting of the
cast-iron head which it encircles, while the cone joint is sufficiently
yielding to allow for the variable expansion in the length of the
tubes.
A modification of this mode of tying the tube heads together is illus-
trared at Figures 7, 10, and 11. Instead of one central tie bar d two tie
bars are used which terminate (see Fig. 7) in a 1 head, the shoulders of
which take on to projections h cast in the bottom head c¹. By these
arrangements ready access is provided for cleaning the tubes a and raking
out any deposit that may have taken place therein.
The last part of our Invention relates to a mode of protecting the
joints of the tube heads from the action of the flame, and of affording

page_text: facilities for examining them. This we effect by grooving each side of
the head, or connecting pieces c to receive (when put together) thin
fire-bricks or plates of metal, as shown at Figures 10 and 11. We thus
form a baffling wall or partition which will shield the joints from the
destructive action of the flame and heated gases of the furnace.
Having now set forth the nature of our Invention of "Improvements
in 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. The arrangement of boilers above described with reference to
Sheets I. and II. of the Drawings, whereby the tube sections are pro-
vided with combustion chambers that admit of facile removal for the
withdrawal both of the nests of tubes and of the furnace tubes for
repairs.
Secondly. The arrangement of double furnace boiler composed of tube
sections, as described with reference to Sheet III. of the Drawings.
Thirdly. The means above described with reference to Fig. 7,
Sheet IV., for securing the tubes to the tube heads.
Fourthly. Connecting the tube heads together by tie bars and double
coned collars, as described with reference to Sheet IV. of the Drawings.
Lastly. The means above described for protecting the joints of the
tubes from the action of the fire.
In witness whereof, we, the said James Howard and Edward
Tenney Bousfield, have hereunto set our hands and seals, the
Seventh day of July, in the year of our Lord One thousand eight
hundred and seventy-four.