IMPROVEMENTS IN STEAM BOILERS
Year: 1876

page_text: LETTERS PATENT to Hazelton Robson Robson, of Glasgow, in the County of
Lanark, North Britain, Engineer, for the Invention of "IMPROVEMENTS IN
STEAM BOILERS."
Sealed the 4th July 1876, and dated the 7th January 1876.
PROVISIONAL SPECIFICATION left by the said Hazelton Robson Robson at
the Office of the Commissioners of Patents on the 7th January 1876.
HAZELTON ROBSON ROBSON, of Glasgow, in the County of Lanark, North Britain,
Engineer. "IMPROVEMENTS IN STEAM BOILERS."
This Invention comprises improvements designed to prevent the injury to which
certain classes of steam boilers, and more especially marine and other boilers with
internal fires, are liable from unequal expansion when being first heated.
In boilers with internal fires, or which are heated otherwise than on their under
sides, the water in the bottoms of the boilers remains cold for a long time after
lighting the fires; and the upper parts of the boilers become considerably heated
and expanded before the bottom parts, so that very injurious strains are produced
between the different parts.
It has been proposed to prevent the injury referred to by appliances requiring
the use of steam from a donkey boiler or other separate boiler; but by the present
Invention provision is made in the boiler itself to secure the object in view, so that
the boiler may be independent of external assistance which is in many cases not
available, or the application of which is liable to be neglected.
The Invention consists in fitting in the flame chambers, or flues, or furnace spaces
pipes, or tubes, having their lower ends in as close communication as possible with
the lowest parts of the boilers, whilst their upper ends communicate with the
higher parts; or in existing boilers, or boilers.to be made like existing boilers, with
tubes or pipes traversings the flame, chambers, flues, or furnace spaces, such tubes
having their ends at lower and higher levels, the Invention, may be carried out by
altering or adding to such tubes or pipes in a manner to secure the formation of
strong and suitably, directed: currents: of water through them when the fires are
lighted.
It is in all cases essential in order to obtain the through, current that the outlet
from the upper end of the tube or pipe shall be more contracted than the inlet at
the lower and

page_text: In marine or other boilers with large conical water tubes in the flame chambers
or flues, the larger ends of the tubes being uppermost, no sufficient current
ordinarily passes through the tubes; and in such cases the upper ends of the tubes
must be contracted by fitting in annular plates, or otherwise, so that only the
heated water and steam can pass through at the upper end, and so that the place of
such water and steam must consequently be taken by successive supplies from
below. It is also essential in such cases to attach to the bottoms of the tubes short
tubes or guide shells to lead the water to the tubes from the lowest parts of the
boilers.
With the described arrangements the fires soon after being lighted cause currents
of water to pass up through the tubes, and as these currents proceed from the
lowest parts of the boilers and take thence the cold water, the warmer water gets
to the bottom without delay and heats up the bottom of the boiler shell so as to
prevent strain from unequal expansion.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Hazelton Robson Robson in the Great Seal Patent Office on the 4th
July 1876.
HAZELTON ROBSON ROBSON, of Glasgow, in the County of Lanark, North Britain,
Engineer. "IMPROVEMENTS IN STEAM BOILERS."
My said Invention comprises improvements designed to prevent the injury to
which certain classes of steam boilers, and more especially marine and other
boilers with internal fires, are liable from unequal expansion when being first
heated.
In boilers with internal fires, or which are heated otherwise than on their under
sides, the water in the bottoms of the boilers remains cold for a long time after
lighting the fires; and the upper parts of the boilers become considerably heated
and expanded before the bottom parts, so that very injurious strains are produced
between the different parts.
It has been proposed to prevent the injury referred to by appliances requiring
the use of steam from a donkey boiler, or other separate boiler; but by my present
Invention provision is made in the boiler itself to secure the object in view, so
that the boiler may be independent of assistance from another boiler, which is in
many cases not available, or the application of which is liable to be neglected.
My Invention consists in fitting in the flame chambers, or flues, or furnace
spaces of the boiler, pipes or tubes having their lower ends in as close communi-
cation as possible with the lowest parts of the boilers, whilst their upper ends
communicate with the higher parts. Or in existing boilers, or boilers to be made
like existing boilers, with tubes or pipes traversing the flame chambers, flues, or
furnace spaces, such tubes having their ends at lower and higher levels. My In-
vention may be carried out by altering or adding to such tubes or pipes in a
manner to secure the formation of strong and suitably directed currents through
them when the fires are lighted.
It is essential in order to obtain the through current that the outlet from the
upper end of the tube or pipe shall be more contracted than the inlet at the lower
end. It is also essential that the tubes or pipes shall receive the water into their
lower ends from the very lowest parts of the boiler, short tubes being attached to
them for the purpose within the lower water spaces if necessary.
And in order that my said Invention and the manner of performing the same
may be properly understood, I hereunto append a Sheet of explanatory Drawings,
to be herein-after referred to, and showing the application of my improvements
to a well-tried form of [marine boiler. In these Drawings the same reference
numerals are used to mark the same or like parts wherever they are repeated.
Figure 1 of the Drawings is a vertical section of a tubular marine boiler fired

page_text: from both sides, the furnaces 1, 2, being back to back, and both at their inner ends
communicating with a central flame chamber 3, from which the fire gases pass
through the two sets of tubes 4, 5, to smoke boxes at the outer sides (but not
shown). Figure 2 is a vertical section, as at right angles to Figure 1, of the upper
part of the flame chamber 3. In the flame chamber 3 there is, in this example, a
large conical water tube 6 placed vertically, but with such a tube 6 as ordinarily
fitted no sufficient current is produced, when the boiler is being freshly heated up,
to cause a uniform temperature to prevail throughout the water in the boiler, and
the injurious strains arising from differential heating, as herein-before mentioned,
are not prevented. I, however, cause the tube 6 to act with complete effect for the
purposes of my Invention by fitting a plate 7 at the upper opening so as to contract
the outlet to a narrow annular orifice, and by fitting a short tube 8 in the bottom
end so as to project through the bottom water space 9 nearly to the bottom of the
boiler.
With the parts so fitted the fires are no sooner lighted than the heat acting
on the tube 6 causes strong currents of water to pass up its sides; and as the
plate 7 above prevents water from descending by the centre of the tube, these
upward currents must be supplied from the bottom end of the tube, and through
the action of the added tube 8, necessarily from the very lowest part of the boiler.
In this way a through circulation of the water is set up and maintained, and the
whole body of water is kept at so nearly uniform a temperature as to avoid all
injurious strains between the different parts of the boiler.
There may of course be two or more tubes (6) fitted and arranged in the manner
herein-before indicated so as to produce the desired circulation.
Having thus particulary described my said Invention and the manner of per-
forming the same, I have to state that I do not restrict myself to the precise details
herein described, with reference to the accompanying Drawings, but that what I
believe to be novel and original, and claim as the Invention secured to me by the
herein-before in part recited Letters Patent is, the fitting of marine and other
boilers having internal fires, or heated otherwise than on their under sides, with
tubes or pipes, arranged substantially as and for the purpose herein-before
described.
In witness whereof, I, the said Hazelton Robson Robson, have hereunto set my
hand and seal this First day of July. in the year of our Lord One thousand
HAZ. R. ROBSON. (L.S.)