IMPROVEMENTS IN STEAM BOILERS."
Year: 1876

page_text: LETTERS PATENT to Henry Septimus Coleman, of Chelmsford, in the County
of Essex, for the Invention of "IMPROVEMENTS IN STEAM BOILERS."
PROVISIONAL SPECIFICATION left by the said Henry Septimus Coleman at
the Office of the Commissioners of Patents on the 12th December 1876.
HENRY SEPTIMUS COLEMAN, of Chelmsford, in the County of Essex.
MENTS IN STEAM BOILERS."
(5
IMPROVE-
My Invention of improvements in steam boilers has for its object to lessen the
consumption of fuel, and to afford greater facilities for cleaning out the boiler.
According to my Invention the boiler is constructed of two barrels or shells,
placed the one above the other, and connected together at intervals by short vertical
tubes. These tubes are, by preference, of slightly tapering or conical form, and
have the larger end uppermost, and within these tubes are suspended circulating
tubes, being straight vertical tubes of smaller diameter extending upwards a short
distance into the upper shell and downwards to within a few inches of the bottom
of the lower shell. These tubes may be flared at the upper end to promote the
circulation of the water, which flows down through the inner tubes and up between
the inner and outer tubes. The inner tubes are supported by bridge pieces or other
removable supports to admit of the tubes being raised out of the way for the
purpose of cleaning the boiler; and in order to still further facilitate this operation
the tubes inay be constructed in two or more parts, sliding telescopically within
one another or jointed together, so that the tubes may be readily shortened or
removed when required.
The boiler is set in brickwork, as usual, and is fired beneath the lower shell, the
products of combustion passing to the back end of the boiler and returning to the
front end through flues enclosing the upper part of the lower shell, and again
returning to the chimney at the back end through other flues enclosing the vertical
connecting tubes and the lower part of the upper shell; or the draught may be
otherwise arranged.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Henry Septimus Coleman in the Great Seal Patent Office on the
12th June 1877.
HENRY SEPTIMUS COLEMAN, of Chelmsford, in the County of Essex. “IMPROVE-
MENTS IN STEAM BOILERS."
My Invention relates to what are known as double boilers, and its object is to
lessen the consumption of fuel by maintaining such a circulation of water as will
effectually prevent the formation of deposit on the bottom of the lower barrel of
the boiler, and reduce the incrustation generally. The boilers to which my
Invention relates have two barrels or shells, placed one over the other, with short
vertical connecting tubes at intervals, and my Invention consists in producing and
maintaining a vigorous circulation of the water from the bottom of the upper shell
to the bottom of the lower shell (that is to say, to the surface of the plates exposed
to the action of the fire) and from the upper part of the lower shell back to the upper
shell by means of circulation tubes applied in or to the connecting tubes above
mentioned, and extending downwards to within a few inches of the bottom of the
lower shell.
There may be a circulation tube in each connecting. tube or in every alternate
one only. In the former case, the circulation tubes would be of about half the
sectional area of the outer or connecting tubes in which they are placed, and they
would be extended a short distance upwards into the upper barrel and preferably
flared to promote the circulation of the water which, in this case, flows down
through the inner tubes and up between the inner and outer tubes. In the other
case the circulation tubes would fit in and form a continuation of the connecting
tubes, and the water would pass down the circulation tubes and rise through the
intermediate connecting tubes. In either case the circulation tubes are so sup-
ported as to be readily removed out of the way when cleaning the boiler, and I
may provide a longitudinal shaft in the upper shell to raise all the tubes simul-
taneously. The tubes may also be constructed in two or more parts, sliding
telescopically one within the other, so as to be readily shortened for removal.
DESCRIPTION OF DRAWINGS.
Figure 1 is a longitudinal section, and Figure 2 a transverse section of a double
boiler provided with a circulation tube in each of the connecting tubes.
The upper barrel or shell A and the lower one B are connected as usual by short
tubes C of slightly conical form with their larger ends uppermost to facilitate the
upward passage of the steam and water; D are the circulation tubes, one in each
tube C rising a few inches within the upper shell A, and descending to about three
or four inches of the bottom of the lower shell B. The upper ends D¹ are flared
and the tubes D are supported by three feathers or bent strips of metal E attached
to them and fitting in the conical tubes C, and also by short legs F resting on the
bottom of the lower shell. The arrows indicate the circulation of the water, which
descending through the tubes D strikes against the bottom of the lower shell, and
by this scouring action effectually prevents the deposit of sediment there, whilst the
incrustation generally is much reduced by the rapid circulation of the water
throughout the two boilers, as above described.
The tubes D may be constructed in two or several lengths fitted to slide
telescopically one within the other, as shown, to facilitate their insertion and
removal; and in order to raise the whole of the tubes out of the way at once I
may provide a longitudinal shaft G, mounted in suitable brackets within the upper
shell, and connect all the tubes D.to said shaft by short lengths of chain. A man-
hole in the upper shell is opened and a winch handle applied to the squared end of
the shaft in order to turn it.
Figure 3 is a part longitudinal section
and
part elevation of a similar boiler,

page_text: with the circulation tubes in each alternate connecting tube only. The same letters
of reference indicate the same parts as before.
It will be seen that the circulation tubes D fit tightly in the lower ends of the
connecting tubes C, so as to form a downward continuation thereof extending to
within a few inches of the bottom of the lower shell. In this case the water can
only pass down through those of the tubes C which are provided with circulation
tubes, and up through the intermediate tubes C as indicated by the arrows, the
circulation being from the bottom of the upper shell to the bottom of the lower
shell and back to the upper shell as before.
In either case the boiler is set in brickwork as usual, as represented in Figure 2,
and is fired beneath the lower shell B, the products of combustion passing to the
back end of the boiler and returning through the flues H, H, enclosing the upper
part of the lower shell, and again returning to the back end through the flues I, I,
enclosing the tubes C and the lower part of the upper shell; or the draught may be
otherwise arranged.
Having described the nature of my Invention and the manner of performing the
same, I declare that what I claim as iny Invention to be protected by the herein-
before in part recited Letters Patent is, in a double boiler consisting of two shells
connected by tubes, as specified, obtaining a vigorous circulation of water from the
bottom of the upper shell to the bottom of the lower shell and from the upper part
of the lower shell, back to the upper shell, by the employment of circulating tubes
applied in or to the said connecting tubes, and extending down nearly to the bottom
of the lower shell, substantially as shown and described.
In witness whereof, I, the said Henry Septimus Coleman, have hereunto set
my hand and seal, this Ninth day of June, in the year of our Lord One
thousand eight hundred and seventy-seven.
H. S. COLEMAN. (L.S.)