IMPROVEMENTS IN STEAM
Year: 1877

page_text: LETTERS PATENT to William Menzies and Charles Blagburn, of Newcastle-
upon-Tyne, Engineers, for the Invention of
BOLLERS"
"IMPROVEMENTS IN STEAM
Scaled the 6th April 1877, and dated the 2nd February 1877.
PROVISIONAL SPECIFICATION left by the said William Menzies and Charles
Blagburn at the Office of the Commissioners of Patents on the 2nd February,
1877.
WILLIAM MENZIES and CHARLES BLAGBURN, of Newcastle-upon-Tyne, Engineers.
"IMPROVEMENTS IN STEAM BOILERS."
Our Invention relates more particularly to marine boilers, and consists of
improvements having for their object promoting the circulation of the water in the
boiler, and thereby equalizing the heat and preventing the chemical or galvanic
action which attacks the under side of the flues and the interior of the bottom of
the boiler, and also the prevention of priming by allowing a passage to the bottom
of the boiler of water to replace what is used in the generation of steam.
In carrying out our Invention as applied for example to a double flued multi-
tubular marine boiler, we arrange between the two flues and the two sets of hori-
zontal fire tubes a vertical tube or series of vertical tubes, by preference of a bell-
mouthed or expanded shape at their upper and lower ends, and opening at their
upper ends which are situate at or about the level of the top row of horizontal fire
tubes into the water space above, and at their lower ends into the water space
below. By means of this arrangement the water is maintained in circulation, that
is to say, currents are constantly passing from the upper water space down the
vertical tubes to the lower water space, and thence by the semi-annular water space
returning to the upper water space, and then again down the vertical tubes, and
again circulating back to the upper water space, and so on in succession, whereby the
advantages and results before-mentioned are obtained.
The vertical tubes may be of an oval, round, rectangular, or other suitable form,
connected by plates, and built in convenient sections so that they can be passed
through the ordinary man-hole, and bolted together in such a manner as to form a
partial division of the water space between the nests of tubes in multitubular or
other boilers from about the working level of the water to any convenient distance

page_text: below the fire-bars for the purpose of promoting a better circulation by preventing
the steam generated on the furnace crowns and lower tubes from obstructing the
free passage of the water to the bottom of the boiler. This result is attained by
the vertical tubes forming a clear passage downwards for the hot water after having
parted with its compliment of steam, thereby causing a perfect circulation and pre-
venting the chemical and galvanic action which corrodes and pits the internal
surfaces of marine boilers under the fire-grate level. As moreover the apparatus is
self-acting and self-contained it requires no attention, it also serves to increase the
efficiency of the boiler by causing a more perfect circulation and thereby diminishing
priming. Similar tubes or sections of tubes or plates may also be fitted to the
inside skin of the boiler shell under the water line for a similar purpose.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Menzies and Charles Blagburn in the Great Seal Patent
Office on the 2nd August 1877.
WILLIAM MENZIES and CHARLES BLAGBURN, of Newcastle-upon-Tyne, Engineers.
"IMPROVEMENTS IN STEAM BOILERS."
Our said Invention relates more particularly to marine boilers, and consists of
improvements having for their object promoting the circulation of the water in the
boiler and thereby equalizing the heat and preventing the chemical or galvanic action
which attacks the under side of the flues and the interior of the bottom of the boiler,
and also the prevention of priming and increasing the evaporative efficiency of the
boiler.
In carrying out our said Invention as applied for example to a double flued
multitubular marine boiler, we arrange between the two flucs and the two sets of
horizontal fire tubes a passage or series of passages in a vertical plane, and opening
at their upper ends which are situate at or about the level of the top row of hori-
zontal fire tubes into the water space above, and at their lower ends into the water
space below. These passages may consist of tubes of an oval, rectangular, or other
elongated section, or of a cluster or series of tubes of a round or other section having
an equivalent aggregate area; or the passages may be formed of double plates, but
in all cases the passages terminate at their upper extremity at about (but below)
the water level, and at their lower extremity below the level of the fire-bars.
In the case of triple flued boilers a water circulating passage or series of passages
may be employed between each outer flue and the central flue, and additional
passages may be arranged around the sides of the boiler at its interior if desired.
And in order that our said Invention may be fully understood we shall now
proceed more particularly to describe the same, and for that purpose shall refer to
the several Figures on the annexed Sheet of Drawings, the same letters of reference
indicating corresponding parts in all the Figures.
Figures 1 and 2 of our Drawings represent respectively a longitudinal and trans-
verse section of a doublo flued multitubular boiler with two vertical circulating
tubes of an elongated section arranged between the flues..
Figure 3 represents a similar view to Figure 1, but with one of the circulating
tubes shewn inclined.
Figure represents a transverse section of a triple flued multitubular boiler with
water circulating tubes arranged both between the flues and on the outer sides of
the outer flues at the sides of the boiler.
Figures 5 and 6 represent a similar boiler to that shown in Figures 1 and 2, but
with double plates substituted for tubes.
A is the outer shell of the boiler; B, B, are the flues; and C, C, are the fire tubes.
D, D, are the water-circulating passages terminating at their upper ends at about
'the level of the water in the boiler, but below the same, and at their lower ends
below the level a of the fire-bars.

page_text: In the arrangements illustrated in Figures 1, 2, 3, and 4, the passages consist of
tubes of an elongated section for which a series of tubes of a round or other section
having an equivalent aggregate sectional area may be substituted.
In the modification shewn in Figures 5 and 6 double plates are employed
extending from the front of the boiler at b nearly to the flame box E. In all cases
however we prefer to make the passages bell mouthed, or expanded at their upper
ends, as shewn at c.
When the Invention is applied to boilers with external furnaces the lower ends
of the water-circulating tubes (if tubes are employed) may be fitted with an inverted
hood, which whilst admitting of the egress of water will form a trap for preventing
the entrance of steam. The tubes or plates are made in convenient sections so as to
admit of their being introduced through the ordinary man-hole and subsequently
bolted together.
By means of our said Invention a partial division of the water space is obtained
so as to prevent the steam generated on the furnace crowns and lower fire tubos
from obstructing the free passage of the water to the bottom of the boiler. The
water is thus maintained in circulation, that is to say, currents are constantly
passing from the upper part of the boiler down the water tubes or passages D to
the lower part of the boiler (the hot water descending after having parted with its
compliment of steam), and the currents thence return through the main body of
water in the boiler, as indicated by the arrows, to the upper part, and then again
pass down the water tubes or passages D and again return to the upper part, and so on
in succession. The boiler shell consequently is maintained throughout. at a uniform
temperaturo, whereby the chemical or galvanic action which corrodes and pits the
internal surface of marine boilers under the fire-grate level is obviated. By reason
moreover of the constant circulation the evaporative efficiency of the boiler is
increased, priming is also prevented, a clear passage being provided for the water
downwards after it has parted with its compliment of steam. The apparatus is
self-contained, and its action is automatic and continuous, it being maintained
without any attention so long as the fires are kept up, in lieu of the circulation
ceasing immediately the steam is raised, as is the case where donkey engines and
other ordinary external auxiliary apparatus are employed for the purpose.
Having now described and particularly ascertained the nature of our said Inven-
tion, and the manner in which the same is or may be used or carried into effect, we
would observe in conclusion that what we consider to be novel and original, and
therefore claim as the Invention secured to us by the herein-before in part recited
Letters Patent is, the application and use to and in steam boilers of water-circulating
passages or tubes of an elongated section, or of a round or other section, and
employed in clusters or series so as to obtain an equivalent aggregate sectional area,
such passages or tubes extending from about the level of the water in the boiler,
but below the same, to any convenient point below the level of the fire-bars, sub-
stantially as and for the purposes herein-before described.
In witness whereof, we, the said William Menzies and Charles Blagburn, have
to this our Specification, set our hands and seals, this Twentieth day of July,
One thousand eight hundred and seventy-seven.
W MENZIES.
(L.S.)
CHARLES BLAGBURN. (Ls.)