IMPROVEMENTS IN STEAM BOILERS
Year: 1874

page_text: LETTERS PATENT to Charles Smith, of Hartlepool, in the County of
Durham, and Alfred Alexander, of Cirencester, in the County of
Gloucester, Engineers, for the Invention of "IMPROVEMENTS IN STEAM
BOILERS,"
Sealed the 25th September 1874, and dated the 31st March 1874.
PROVISIONAL SPECIFICATION left by the said Charles Smith and
Alfred Alexander at the Office of the Commissioners of Patents,
with their Petition, on the 31st March 1874.
We, CHARLES SMITH, of Hartlepool, in the County of Durham, and
ALFRED ALEXANDER, of Cirencester, in the County of Gloucester,
Engineers, do hereby declare the nature of the said Invention for "Iм-
PROVEMENTS IN STEAM BOILERS," to be as follows:-
:-
This Invention has for its object by improved and simplified con-
structions or arrangements to render steam boilers more efficient, safer,
and less liable to derangement than hitherto.
A boiler constructed according to the Invention consists mainly of
one or more horizontal cylindrical shells, having by preference flues or
flue tubes passing longitudinally through them.

page_text: An important feature of the Invention' is the applying of the heat of
the furnace or furnaces to the lateral part or parts of the under half of
cach cylindrical shell, and the having the bottom or lowest part of cach
shell not heated at all, or to only a comparatively small extent. When
the cylindrical shell has a number of tubes through it these are by
preference arranged so as to leave a free vertical space along the middle,
and vertical plates or tubes may be arranged in such middle space to
facilitate the circulation of the water.
It is a special object of the arrangement to produce a through
circulation, the application of the heat to the sides producing rapid
upward currents, whilst complementary currents descend through the
middle space.
The arrangement also has the advantage that any deposits will lic at
the comparatively unheated bottom of the boiler, and not upon the
lateral surfaces exposed to the more intense heat, so that the lateral
plates will transmit the heat with greater facility and be less liable to
injury.
The heat, either of a special furnace or furnaces or the otherwise
wasted heat from puddling, heating, or other furnaces, may be made to
act on the lower lateral parts of the outside of the cylindrical shell or
shells, the fire-gases proceeding along to the back end and then
returning through tubes or flucs through the shell; or the fire-gases
may be made to pass first through the tubes or flues and then in contact
with the lower lateral outer parts of the shells.
.
A great variety of arrangements with two or more cylindrical shells
may obviously be made embodying the features herein-before described.
For example, in the case of a combination of for boiler shells these
touch each other, and there are three furnaces constructed immediately
under the three central lines, so that cachi furnace heats the adjacent
lower lateral parts of two shells.
Additional smaller furnaces may if desired be applied to the outer
sides of the two end shells of the series. The fire-gases pass back from
the furnaces along, under, and between the boiler shells to a flame box or
flue space constructed by preference with external walls of brick across
the back ends of the shells, and the fire-gases have access by this flue
space to the tubes, by which they return to the front ends of the boilers

page_text: to a smoke box or boxes communicating with one or more funnels or
chimneys. Dampers are arranged in the flame box or flue space at the
back to admit of any one of the cylindrical shells being separated from
the others for cleaning or other purpose. The furnaces may be arranged
externally to the front ends of the boiler shells or partly or wholly
beneath their lateral parts.
Кигрианс
filed by the said Charles Smith and Alfred Alexander in the Great
Seal Patent Office on the 29th September 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME; wc, CHARLES
SMITH, of Hartlepool, in the County of Durham; and ALFRED
ALEXANDER, of Cirencester, in the County of Gloucester, Engineers,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
5 Patent, bearing date the Thirty-first-day of March, 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 heirs and successors, give
and grant unto us, the said Charles Smith and Alfred Alexander,
Her special licence that we, the said Charles Smith and Alfred
Alexander, our executors, administrators, and assigns, or such others as
we, the said Charles Smith and Alfred Alexander, 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 Charles
Smith and Alfred Alexander, our executors or administrators, by.an
instrument in writing under our, or their, or one of their hands and
scals, 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.
+
.

page_text: 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 in writing, reference being had to the
accompanying Drawings, that is to say:-
Our said Invention has for its object by improved and simplified
constructions or arrangements to render steam boilers more efficient,
safer, and less liable to derangement than hitherto.
5
A boiler constructed according to our Invention consists mainly of
one or more horizontal cylindrical shells, having by preference flue tubes 1
passing through them..
An important feature of our Invention is the applying of the heat of
the furnace or furnaces to the lateral part or parts of the under half of
each cylindrical shell, and the having the bottom or lowest part of each
shell not heated at all, or to only a comparatively small extent. When 1
the cylindrical shell is fitted with a number of tubes these are by
preference arranged so as to leave a free vertical space up the middle
of the boiler in order to facilitate the circulation of the water.
It is a special object of our improved arrangements to produce a
thorough circulation; the application of the heat to the sides producing 2
rapid upward currents, whilst complementary currents descend through
'the middle space. To still further facilitate the circulation vertical
plates or tubes may be suspended in the middle space between the
'horizontal tubes.
Another special object of our improved arrangements is that any 2
deposits may lie at the comparatively unheated bottom of the boiler,
and not upon the lateral surfaces exposed to the more intense heat, so
that the plates exposed to the fire will transmit the heat with greater
facility and be less liable to injury.
The arrangements also have the advantage of permitting the removal 3
of sludge and the cleaning of the boiler with great ease.
The heat, either of a special furnace or furnaces, or the otherwise
waste heat from puddling, heating, or other furnaces, may be made to
act on the lower lateral parts of the outside of the cylindrical shell, the
fire-gases proceeding along to the back end and then returning through a
the tubes if such are fitted,

page_text: A variety of arrangements with two or more cylindrical shells may
obviously be made embodying the features herein-before described, but
in order that our said Invention and the manner of performing the
same may be properly understood we hereunto append four Sheets of
explanatory Drawings to be herein-after referred to, and representing
four examples of boilers as made with our improvements. In these
Drawings the same reference numerals are used to mark the same or like
parts wherever they are repeated.
Figure 1, Sheet 1, represents a combination of four boiler shells, one
half of the Figure being in front end elevation, and one half in vertical
section; and Figure 8, Sheet 4, is a vertical section as at right angles
to Figure 1. In this example the four shells 1, 2, 3, 4, are placed side
by side in a single row, and are surmounted by a steam chest 5 crossing
over and connected to each of them. There are three furnaces 6, 7, 8,
constructed immediately under the three contact lines of the shells 1, 2,
3, 4, so that each furnace heats the adjacent lower lateral parts of two
shells.,
Additional smaller furnaces may if desired be applied to the outer
sides of the two end shells 1, 4, for example, in the manner shown in
Figure 9, Sheet 4. The fire-gases pass back from the furnaces along,
under, and between the boiler shells to a flame box or flue space 13
constructed with external walls of brick across the back ends of the
shells, and the fire-gases have access by this flue space to the tubes 9,
by which they return to the front ends of the boilers to smoke boxes 10
communicating with funnels or chimneys 11. It will be observed that
the tubes 9 are arranged so as to leave a clear middle space 12 to
facilitate circulation, as hercin-before explained.
Figures 2, 3, 4, 5, Sheet 2, show another mode of combining four
boiler shells 1, 2, 3, 4, Figures 2 and 3 being partly in elevation and
O partly in section and at right angles to each other, whilst Figures 4
and 5 are transverse vertical sections. In this example the boiler
shells 1, 2, 3, 4, are arranged in two pairs placed back to back, each
pair having a single furnace 6, 8, beneath and between their adjacent
lower lateral parts. A single combustion or flame chamber 13 is
5 constructed in a middle space, separating one pair of shells from the
other. An advantage of this arrangement is that a comparatively
smaller quantity of brickwork is required in constructing the combustion

page_text: chamber 13, whilst a more perfect combustion and prevention of smoke
accompany the opposito and alternate firing, which the plan admits of.
Figures 6 and 7, Sheet 3, show an example of our improved boilers,
consisting of a single pair of shells 1, 2, with a single furnace 6 beneath
and between their adjacent lower lateral parts. Figure 6 is one half in
front clevation, and the other half in vertical section, and Figure 7 is a
longitudinal vertical section.
Figure 9, Sheet 4, shows a modification embodying the same essential
features as the others, but with only a single main boiler shell 1, two
small furnaces 14, 15, being arranged to heat the lower lateral parts of
the shell, and their fire-gases combining in a combustion chamber (13)
at the back end, from which they return by tubes 9 to the front: If
preferred a single furnace may be used, and only one side of the shell
be heated in this way.
'
'
'
The Drawings show plainly and in a manner that will be easily
understood by engineers and those practically acquainted with existing
modes of constructing and delineating steam boilers, the modes we
prefer of arranging and adapting the various minor constructive details
and appliances, which may however be modified in various ways.without
interfering with the essential features of our said Invention.
We may remark that the main boiler shells (1, 2, 3, 4,) may bè
arranged as shown in most of the Figures so as to touch each other, or
the individuals of each pair may be placed a little apart, as shown in
Figure 5, Sheet 2, the interspace being covered in with fire-brick or fire
'clay, an arrangement admitting not only of a greater width of fire-grate, a
but also of the shell sides being exposed to the fire heat up to a higher
level.
.
We prefer to lead the feed pipes as indicated at 16, so as to deliver
the water in a downward direction into the middle spaces 12, and to
connect blow-off pipes 17 to the bottoms of those spaces, whilst sludge
or cleaning doors 18 should be provided at the lower parts of the ends
of the boiler shells.
We also prefer to have surface blow-off pipes, as indicated at 19, these
nines being arranged so as to serve a double De br now

page_text: In any of the modifications of our improved boilers the furnaces may
be arranged externally to the front ends of the boiler shells, or partly or
wholly beneath their lateral parts.
Having thus particularly described our said Invention and the manner
of performing the same, we have to state that we do not restrict
ourselves to the precise details hercin described or delineated, but that
what we believe to be novel and original, and claim as the Invention
secured to us by the herein-before in part recited Letters Patent
is,-
1. The constructing of steam boilers so as to comprise one or more
horizontal cylindrical shells with furnace arrangements, such as to apply
the direct fire heat to only the lateral part or parts of the under
half of cach shell, substantially as and for the purposes hercin-before
described.
2. The combining of the mode of applying direct fire heat defined in
the next preceding sentence with the mode of grouping the flue tubes
(9), so as to leave a middle space (12), and thereby facilitate circulation,
substantially as herein-before described.
3. The arranging of two or more horizontal boiler shells, close or
nearly close together, with a furnace beneath and between cach two
boiler shells, and directly heating their adjacent lower lateral parts,
substantially as herein-before described.
In witness whereof, I, the said Charles Smith, on behalf of myself
and the said Alfred Alexander, have hereunto set my hand and
scal, this the 28th (Twenty-eighth) day of September, in the
year of our Lord One thousand eight hundred and seventy-
four.