Improvements in the Construction of Low Pressure Steam Boilers.
Year: 1888

page_text: Date of Application, 25th Jan., 1888
Specification Accepted, 2nd Mar., 1388
Improvements in the Construction of Low Pressure Steam
Boilers.
I, HENRY DAVEY, of 3 Prince's Street, Westminster, in the county of Middlesex,
Engineer 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 :-
In my Specifications Nos. 3833 and 15,185 of 1884, No. 1981 of 1885, and
Nos. 2930 and 5607 of 1886, 1. have described various forms of Low Pressure Steam
Motors and Boilers specially designed to ensure safety against explosion and to require
comparatively little attention.
My present invention relates to improvements in the construction of Low Pressure
Steam Boilers, which are, among other purposes, applicable to the Boilers of the Low
Pressure Steam Motors described in the Specifications referred to above. Fig. 1 of
the accompanying drawings is a vertical section illustrating the application of my
invention to a combined Low Pressure Steam Motor and Boiler such as are described
in my Specifications Nos. 3833 and 15,185 of 1884. Fig. 2 is a vertical section, and
Fig. 3 a sectional plan, illustrating the application of my invention to a separate Low
Pressure Steam Boiler, such as are described in my Specifications No. 1981 of 1885,
and Nos. 2930 and 5607 of 1886.
The general construction shewn in Fig. 1 is similar to that described in my
Specifications Nos. 3833 and 15,185 of 1884 above referred to; I will therefore
describe only the modifications shewn in the drawing.
The Boiler B, Fig. 1, is secured to a bedplate Z, to which is also secured the fire-
box A. The said bed plate has two projections H H for supporting the firebars D ;
and is further provided with a damper-door O, which slides on a plate P, rivetted to
the base Z, in front of the opening Qin the said base; and by adjusting the position
of the said damper-door in front of the said opening the supply of air may be reduced
to any degree or entirely cut off. The fire-box A is provided with additional heating
surface by the tubes I, I, &c.; the said tubes being placed at an angle so that the water
heated in them may in rising produce a general circulation of the water in the boiler.
C is a mouth piece fastened to the firebox A, which serves for the introduction of fuel
into the firebox, and its joint with the boiler B is made by means of packing in the

page_text: recess L which is kept tight by the ring M which carries the fire door N. J is a
block of fire brick which prevents the fuel from lodging behind the projection H.
The cylinder E and the cylindrical guide tare made in one piece and fastened to
the boiler, and the cylinder is so arranged that the steam is allowed a free passage
around it. The distribution of steam in the cylinder, its subsequent exhaustion into
the condenser K, and the extraction of the condensed water from the latter, are
effected in substantially the same way as described in my Specification No. 15,185
of 1884.
The feed water is supplied to the boiler by means of similar apparatus to that
described in the Specifications above referred to. V is the blow-off valve box
containing an ordinary single beat valve and provided with a pipe R for conducting
the surplus steam into the flue G.
In Figures 2 and 3, B is a cylindrical boiler secured to the base plate Z; the said
base plate is similar to that shewn in Fig. 1, and its parts are designated by the same
letters. The fire-box A is of large capacity and is provided with a hopper h, which
enables it to hold sufficient fuel to last for several hours. The tubes, &c., are
similarly disposed to those shewn in Fig. 1. W is a baffle plate. The feed apparatus
shewn at X is the same as that described in my Specification No. 15,185 of 1884.
The heated gases given off from the fuel do not ascend through the coke as in the
boiler described in my Specification No. 5607 of 1886, but pass around the
tubes I 1, &c., to the flue G. The boiler is shewn covered with non-conducting
material at Y.
Having now described my invention and the manner in which it may be carried
out, I claim,
1. The construction of the Low Pressure Steam Boiler, substantially as described
and illustrated in Figure 1 of the accompanying drawings.
2. The construction of a similar Low Pressure Steam Boiler with the addition of a
large coke space, substantially as described and illustrated in Figures 2 and 3 of the
accompanying drawings.
Dated this 25th day of January 1888.