Improvements in Steam Boilers.
Year: 1891

page_text: Date of Application, 21st Aug., 1891
Complete Specification Left, 18th May, 1892-Accepted, 18th June, 1892
PROVISIONAL SPECIFICATION.
Improvements in Steam Boilers.
I, DAVID HOPE MACBRAYNE, of 119, Hope Street, Glasgow, in the County of
Lanark, North Britain, Shipping Agent, do hereby declare the nature of this
invention to be as follows, that is to say :-
My said invention comprises improvements in certain classes of steam boilers used
for marine purposes, but also applicable for various purposes on land. My object
is with economy in construction, to obtain increased efficiency, and to provide ample
steam space with a comparatively small height of boiler.
In carrying out my invention in the case of a boiler of what is known as the
"haystack" type, according to one modification, I have the horizontal water space
directly over the furnaces made of an annular form, and communicating with, or
extending downwards in, a narrow annular cylindrical water space at the inner ends
of the furnaces. The fire gases ascend past the outer part of the annular water
space first mentioned and within the usual water space formed between the lower
part of the outer shell of the boiler and inner shells enclosing the furnaces and
other parts. The usual combustion chamber is formed above the horizontal annular
water space, and its outer part is crossed by vertical water tubes connecting the
horizontal water space with the upper part of the boiler. The fire gases crossing
the vertical water tubes converge towards the centre of the combustion chamber
but instead of, as in ordinary haystack boilers passing thence directly upwards
through a vertical flue or uptake I cause them to descend through the space
enclosed by the annular cylindrical water space at the inner ends of the furnaces,
and to pass through a smoke box or flue under the boiler to a funnel arranged at
any convenient part outside of the boiler. With this construction the upper part
of the boiler comprising the steam space is not diminished by the ordinary uptake
or flue, and can be made of ample capacity with diminished height.
In another modification a number of fire-gas tubes are substituted for the inner
shell or central descending flue. The vertical dimension of the combustion chamber
may be diminished or varied, and it may or may not be crossed by vertical water
tubes.
The hereinbefore described arrangement according to which the used fire gases
leave the boiler from the bottom or lower part of the combustion chamber or smoke
box is advantageously applicable to various forms of steam boilers.
Dated this Twentieth day of August 1891.
EDMUND HUNT,
Applicant's Agent.
COMPLETE SPECIFICATION.
Improvements in Steam Boilers.
1, DAVID HOPE MACBRAYNE, of 119 Hope Street, Glasgow, in the County
of Lanark, North Britain, Engineer, do hereby declare the nature of this invention
O and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement, that is to say:-
My said invention comprises improvements in certain classes of steam boilers used
for marine purposes, but also applicable for various purposes on land. My object
is, with economy in construction to obtain increased efficiency, and to provide ample
5 steam space with a comparatively small height of boiler.

page_text: In carrying out my invention in the case of a boiler of what is known as the
"haystack" type according to one modification, I have the horizontal water space
directly over the furnaces made of an annular form and extending downwards in a
narrow annular cylindrical water space at the inner ends of the furnaces. The fire-
gases ascend past the outer part of the annular water space first mentioned, and
within the usual water space formed between the lower part of the outer shell of
the boiler and inner shells enclosing the furnaces and other parts, to the usual
combustion chamber formed above, towards the centre of which they converge, and
then descend through the space enclosed by the annular cylindrical water space to
a smoke box under the boiler, and thence to a funnel arranged at any convenient
part outside of the boiler. With this construction the steam space can be made of
ample capacity with diminished height.
In another modification a number of fire-gas tubes are substituted for the inner
shell or descending flue.
And in order that my said invention and the manner of performing the same may
be properly understood, I hereunto append two sheets of explanatory drawings
showing two examples of my improved steam boilers.
Figure 1, on Sheet 1, of the accompanying drawings is a vertical section, and
Figure 2, shows three horizontal sections of one modification.
Figure 3, on Sheet 2, is a vertical section of another modification of my improved
steam boiler.
In Figure 1, on Sheet 1, and Figure 3, on Sheet 2, the water tubes shown in the
combustion chamber although extending completely around the combustion chamber
and descending flue or fire-gas tubes, are shown as only appearing at the sides for
the sake of convenience and simplicity. In these drawings the same reference letters
are used to mark the same or like parts wherever they are repeated.
As shown on Sheet 1, of the drawings I have the horizontal water space, A,
directly over the furnaces, B, made of an annular form, and communicating with
or extending downwards in a narrow annular cylindrical water space, C, at the
inner ends or parts of the furnaces. The fire-gases ascend past the outer part of
the annular water space, A, and within the usual water space, D, formed between
the lower part of the outer shell, E, of the boiler and inner shells, F, enclosing the
furnaces, B, and other parts. The usual combustion chamber, G, is formed above
the horizontal annular water space, A, and its outer part is crossed by vertical water
tubes, H, connecting the horizontal water space with the upper part, J, of the
boiler. The fire-gases crossing the vertical water tubes, H, converge towards the
centre of the combustion chamber, G, but instead of as in ordinary haystack boilers
passing thence directly upwards through a vertical flue or uptake, I cause them to
descend through the downtake or space, K, enclosed by the annular cylindrical water
space, C, at the inner ends of the furnace, B, and to pass through a smoke box or
flue, L, under the boiler to a funnel (not shown) arranged at any convenient part
outside of the boiler. With this construction the upper part of the boiler
comprising the steam space, M, is not diminished by the ordinary uptake or flue
and can be made of ample capacity with diminished height. The downtake or
space (K) enclosed by the water space (C) at the inner ends of the furnace need
not be concentric with the boiler but can be placed as much or as little to one side
as may be practicable or desirable; and the downtake (K) may be of any other
simple form instead of cylindrical, if desired...
In the modification shown in Figure 3, on Sheet 2, a number of fire-gas tubes, N,
are substituted for the inner shell or descending flue, K, through which the fire-
gases can pass to a smoke box (not shown), but which can be arranged as shown in
Figures 1, 2, on Sheet 1, or in any other suitable way. The vertical dimension of
the combustion chamber, G, may be diminished or varied, and it may or may not
be crossed by vertical water tubes, H.
The hereinbefore described arrangement according to which the used fire gases
leave the boiler from the bottom or lower part of the combustion chamber, G, is
advantageously applicable to various forms of steam boilers.

page_text: Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what I
claim is :-
1. The improved construction of steam boiler, substantially as hereinbefore
described and as shown on Sheet 1, of the accompanying drawings.
2. The improved construction of steam boiler substantially as hereinbefore
described and as shown on Sheet 2, of the accompanying drawings.
3. In a steam boiler, a down-take or inner descending flue communicating with
the bottom of a combustion chamber which is above the furnace or furnaces,
substantially as and for the purposes herein before described.
4. In a steam boiler the arrangement of fire-gas tubes communicating with the
bottom of the combustion chamber and the bottom of the boiler substantially as and
for the purposes hereinbefore described.
Dated this Seventeenth day of Man 1802
EDMUND HUNT,
Applicant's Agent.