Improvements in Steam Boilers.
Year: 1891

page_text: Date of Application, 30th July, 1891
Complete Specification Left, 29th Apr., 1892-Accepted, 4th June, 1892
PROVISIONAL SPECIFICATION.
Improvements in Steam Boilers.
I, ROBERT HORN of 201 Kent Road Glasgow, Foreman Boiler Maker, do
hereby declare the nature of this invention to be as follows
:-
This invention relates to boilers for generating steam and especially to marine
boilers.
In carrying out the invention the boiler is divided up into, by preference, three
sections forming fire boxes and each of these fire boxes is fitted with, preferably,
three furnaces so arranged as to give the greatest heating surface possible. The
furnaces are, preferably, arranged in the form of a triangle.
The furnaces may be corrugated or not as desired.
The fire boxes are stayed in the usual manner.
A boiler of this construction whilst generating steam more rapidly than those
made in the ordinary way is not so liable to be injured under forced draught as the
furnaces are smaller and therefore stronger.
Each side of the furnace grate is preferably lined with fire brick.
In a marine boiler with, say, three fire boxes there will be, under this invention,
three or other suitable number of furnaces to each fire box or nine furnaces in all
if three is the number in each fire box.
By dividing the boiler up into sections as herein before described any one or two
of the sections can be damped down and only the other sections, or section as the
case may be, be used for steam raising.
Dated this 29th day of July 1891.
H. D. FITZPATRICK,
70, Wellington Street, Glasgow, Agent.
COMPLETE SPECIFICATION.
Improvements in Steam Boilers.
I, ROBERT HORN of 201 Kent Road, Glasgow, Foreman Boiler Maker, do
hereby declare the nature of this invention and in what manner the same is to
be performed, to be particularly described and ascertained in and by the following
statement:-
This invention relates to boilers for generating steam and especially to marine
boilers.
In carrying out the invention the boiler is divided up into, by preference, three
sections forming fire boxes or combustion chambers and each of these fire boxes is
fitted with, preferably, three furnaces so arranged as to give the greatest heating
surface possible. The furnaces are, preferably, arranged in the form of a
triangle.
By dividing the boiler up into sections as hereinbefore described any one or two
of the sections can be damped down and only the other sections, or section as the
case may be, be used for steam raising.
And in order that my said invention may be properly understood I have hereunto
appended three explanatory sheets of drawings, whereon.
Fig. 1 is a vertical section of one form of a marine boiler as constructed in
accordance with my invention.
Fig. 2 is a longitudinal section of the boiler Fig. 1.
Fig. 3 is a vertical section of another form of the improved marine boiler.
Fig. 4 is a longitudinal section of Fig. 3.

page_text: Fig. 5 is a vertical section of a third form of the improved marine boiler.
Fig. 6 is a longitudinal section of Fig. 5.
On the drawings the same reference letters wherever repeated indicate similar o
like parts.
Referring to Figs. 1 and 2, Sheet 1-
The boiler, as shown in these views, is divided into three sections α, b, c, which
form fire boxes or combustion chambers. a', 6', and c¹ are the walls of the fire boxes
A space for water to circulate is left between each section as shown. In each o
the sections are located three furnaces d, making nine furnaces in all for the boiler
As will be seen the furnaces are shown as only extending partially through the
boiler although they may extend right through and be fired from both ends if s
desired. e are the fire bars, f the bridge, a stays, tubes, i are water circulating
tubes fitted in the back of each section. The water circulating tubes are shown
dotted at Fig. 1.
In order to get the greatest compactness each set of the furnaces, as will be seen
are arranged in a triangular form the furnaces in the centre section being arranged
in the form of a triangle with the apex upwards and the furnaces in the side sections
being arranged in the form of an inverted triangle. The walls of the sections are
curved so as to allow for the furnaces being equally spaced from one another.
This arrangement of nine furnaces for a boiler gives a great amount of heating
surface and consequent great evaporation. The furnaces being smaller in diameter
than usual are therefore stronger.
When the furnaces are swelled or expanded at the fore end as shown at j they
can be easily taken out and replaced.
In the arrangement at Figs. 3 and 4 the furnaces are differently fitted. As will
be seen the centre section has two small size furnaces and one larger furnace
arranged in the form of a inverted triangle. In the side sections a and c only two
furnaces are in this case fitted. As will be seen the four upper furnaces are in line
whilst the three lower ones follow the curve of the boiler plates. The walls of the
fire boxes are curved so as to conform to the position of the furnaces.
The sectional view Fig. 4 shows the large centre furnace as made of corrugated
metal.
In Figs. 5 and 6 the furnaces are arranged, three small ones in the centre section
and only one large furnace in each of the side sections, which latter are, in this
case, very small. This arrangement is suitable for small boilers. The three centre
furnaces are arranged in the form of a triangle.
My improved construction of boiler has the following advantages over the present
forms of construction, viz. :—
Only plain furnaces are required so that with a furnace 30-in., ex-dia. ¾ in. mild
steel plate, there is by Lloyd's rules, 174 lbs. working pressure.
In arranging one furnace above another as shown there are more furnaces in the
same size of boiler, and more heating surface in the furnaces (fully a half more),
the furnaces representing the most effective portion of the heating surface, there i
also about a quarter more heating surface in the combustion chambers and tubes in
proportion to grate surface.
The nine furnaces of 30-in. diameter (see Sheet 1) occupy the same space as
four 44-in. diameter, therefore there is the same quantity of water in the boiler
around the furnaces with the nine as with the four, and the water is much better
divided about the furnaces, which will give a more uniform heat and greatly lessen
the injury caused to boilers by having a small quantity of water at some parts and
a much greater quantity at others.
There is less water in bottom of boiler, although the furnaces are the same
distance from the shell, the six furnaces around the shell being smaller, the water is
divided over more parts in smaller quantities, and the heat being so near the shell
the water will be much warmer at the bottom which will cause a better circulation,
and the chance of leakage in bottom of boiler will be greatly reduced.
With a circulation tube in each combustion chamber as showu at Figs. 1 and 2 of

page_text: the drawings, the three fires acting on one tube will make steam very fast and cause
a good circulation through those tubes from the bottom of boiler.
It is well known that the best part of the coal is lost in the smoke, caused by
heavy firing, and carried through the tubes and up the funnel, and soot being a
non-conductor, a great part of the heating surface in the tubes is lost by the soot
gathering in them. The fire from two of the furnaces will consume the smoke of
the third while coaling it, making this boiler almost smokeless, and cause little
difference in the steam, and the one fire will improve the draught of the other.
If the furnaces are swelled in. all round at fore-end as shown at j, four inches
long, they can be easily renewed by cutting out the rivets at both ends.
With the small size of furnaces only single riveting is required, giving a closer
pitch of rivets and less double plate above fire.
When using forced draught, it will be divided over more parts and will conse-
quently not be so sore on furnace sides and stays in combustion chambers.
The furnaces can be riveted at both ends, and caulked outside and in when the.
boxes are out of the shell, where there will be plenty of room.
The furnace and other parts can be easily cleaned.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. A boiler constructed and having its furnaces arranged, substantially as herein-
before described with reference to Figs. 1 and 2 and the modifications at.
Figs. 3, 4, 5 and 6 of the drawings annexed and for the advantages set forth.
Dated this 27th dow of Annil 1900
H. D. FITZPATRICK,
70, Wellington Street, Glasgow, Agent.
H. D. FITZPATRICK,
70, Wellington Street, Glasgow, Agent.