Improvements in Steam Boilers.
Year: 1895

page_text: Date of Application, 14th Aug., 1895-Accepted, 14th Sept., 1895
Improvements in Steam Boilers.
I, GEORGE JOHNSTON, of Mosesfield, Springburn, in the County of Lanark,
North Britain, 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, that is to say :-
My said invention has for its object to improve the construction of steam boilers ;
and a boiler as made with my improvements is represented on an accompanying
sheet of explanatory drawings.
Figure, 1, of the drawings is a vertical section; and Figure, 2, is a horizontal
section as at the lower part of the boiler. In these drawings the same reference
letters are used to mark the same or like parts wherever they are repeated.
My improved boiler, which is of the vertical type, comprises an upper annular
cylindrical vessel, A, in which is space for steam and for the upper part of the
water. The bottom of the vessel, A, is connected by comparatively large vertical
tubes, B, with an annular water space, C, forming the bottom of the boiler.
From the bottom water space, C, circular sets of water tubes, D, E, F, extend up
to the upper part of the vessel, A, being fixed in the inner cylindrical shell, G, of
that vessel. The upper part of the shell, G, is encompassed by a cylindrical
shell, H, between which and the shell, G, steam and water entering from the upper
ends of the tubes, D, E, F, descend in a manner to separate the steam from the
water.
The furnace or combustion chamber is the space, J, within the lower parts of
the tubes, D, E, F, and these tubes constitute the main heating surface, the water
and steam passing up them, and the water returning downwards through the
tubes, B. The boiler is designed to be heated by means of a liquid or gaseous
hydrocarbon, any suitable burner being arranged in the space, K, indicated by
dotted lines in Figure, 1; and a slab, L, also indicated by dotted lines, being
placed centrally above the burner to deflect the flames annularly.
The heating
tubes, D, E, F, are curved as shown so that the fire gases may pass effectively
amongst them; and a firebrick block, M, supported centrally by some of the
innermost tubes, D, curved inwards for the purpose, causes the fire gases to pass
upwards amongst the upper vertical parts of the tubes on the way to the uptake or
chimney, N.
The constructive details are susceptible of variation but what are shown and
preferred are as follows. The vessel, A, is made with outer and inner cylindrical
shells, P, and G, the lower part of the inner shell being flanged outwards and
riveted to the outer shell. Rings, Q, R, are riveted to the upper ends of the
shells, P, G, and an annular top plate, S, is bolted to these rings, the plate being
grooved to receive the edges of the shells, P, G, so as to make tight joints. The
bottom water space, C, is formed by an annular casting or forging, T, in section
shaped like an inverted channel, to which is bolted an annular bottom plate, V,
the joints being rendered tight by ribs on one fitting grooves in the other. The
heating tubes, D, E, F, may be fixed in the ordinary or any suitable way, but the
tubes, B, for the descent of the water are by preference fixed by means of screw
nuts as shown.

page_text: 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. The combination of parts constituting my improved steam boiler substantially
as hereinbefore described and as shown in the accompanying drawings.
2. In a vertical steam boiler an upper annular cylindrical vessel connected by
descending water tubes to a bottom water space from which curved heating water
tubes extend upwards their upper parts being in the central space encircled by the
upper annular vessel and their upper ends being connected to the upper part of
that vessel substantially as herein before described.
Dated this Thirteenth day of August 1895.
EDMUND HUNT,
Applicant's Agent.