Year: 1888

page_text: Date of Application, 7th Feb., 1888
Specification Accepted, 9th Mar., 1888
I, ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex, M.I.M.E.
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:-
The present invention refers to improvements in steam generators such improve-
ments consisting in introducing highly heated air to the furnace, which is entirely
separated from the boiler thus producing almost entire combustion of the fuel and
consequently an increase of the heating power and also in conducting the products of
combustion through return flues or tubes which pass upwards from the dome of the
furnace for a short distance and are then bent downwards to the bottom of the boiler
the heat coming thus into close contact with surfaces surrounded by water only.
The bent form of the flues admits of compensation for any expansion, thus preventing
any danger of leaking, and all surfaces in contact with hent and water are easily
reached for the purposes of cleaning and repairing; the working expenses are also
reduced by a considerable saving of fuel.
In the accompanying drawings :-
Fig. 1 represents a vertical section of the boiler with its furnace and foundation.
Fig. 2 is a sectional plan of the boiler above the return flues.
Fig. 3 is a sectional plan of the foundation and the furnace above the fire bars.
The boiler A consists of two parts i.e. the inner and lower part b with the firebox c
and the return flues d reaching upwards from the dome of the firebox and then turning
down to the bottom of the boiler; and the outer shell a of the boiler, which can be
easily detached from the inner and lower part b.
The boiler A is mounted on a circular foundation B which consists of the outer wall f
the furnace g with the fire grate i and the refractory wall h also of the stoke hole with
the removable block K for regulating the combustibles on the firegrate i and provided
with a door . Through a further door m in the outer wall of the foundation the ash-
pit n can be reached. The latter is filled with water for the purpose of preventing
any melting of the fire bars and of assisting the combustion of the fuel.

page_text: The bottom of the boiler forms with the outer wall of the foundation and the
furnace g a circular smoke box into which open the return flues & and which is in
connection with the shaft R. Under this smoke box is formed round the furnace ga
circular air chamber p into which the air for the combustion enters through the
opening o which may be closed if desired. The air will be highly hoated in this
chamber by the heat radiated from the bottom of the smoke box and the wall of the
furnace and passes underneath the fire grate through the opening Z. This opening is
preferably placed as shown in figure 3, although it is shown in figure 1 in a different
position to better illustrate how the heated air passes underneath the fire grate.
The return flues d are cleaned by means of a jet of steam sent through them
simultaneously from a tube S arranged in the smoko box e.
Having now particularly described and ascertained the nature of the said invention,
as communicated to me by my foreign correspondent, and in what manner the same is
to be performed, I declare that what I claim is :-
A steam generator constructed in two parts as described and provided with return
tubes or flues d in combination with the smoke box e the air heating chamber p and
the furnace and fire grate situated outside the boiler and provided with the removable
block K the whole constructed and operating substantially as described and illustrated
in the accompanying drawings.