Improvements in Cornish Boilers.
Year: 1897

page_text: Date of Application, 29th Sept., 1897-Accepted, 20th Oct., 1897
COMPLETE SPECIFICATION.
Improvements in Cornish Boilers.
We, HERMANUS THOMASSEN, of 2%, Oosterparkstraat 215, Amsterdam, in the
Kingdom of Holland, Engineer, and JACOBUS KROP, of 110, Westerstraat,
Amsterdam, aforesaid, Mechanic, 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:―
Our invention relates to an arrangement of Cornish steam boiler by which the
gases of combustion, as they leave the flame-tube are thoroughly mixed with each
other and with the air required for combustion, and again concentrated, perfect
combustion and increased yield of heat to the walls of the flame-tube being thus
effected.
The arrangement, which may be applied to any boiler of the type named,
including those furnished with Galloway tubes, consists in placing a ring at the
hinder end of the flame-tube and at a short distance in front of it a disc, this latter
leaving a small annular space between itself and the wall of the flame-tube. The
area of this annular space between the disc and the flame-tube and also that of
the central aperture of the ring referred to are each equal to the area of the free
space over the fire-bridge.
The effect of this arrangement is that the grate-area may be reduced to the
extent of one-half, and a saving of fuel to the amount of from twenty-five to
fifty per cent. effected, whilst the production of steam remains the same.
The accompanying drawing illustrates the application of our invention to a
Galloway boiler:
Figure 1 is a longitudinal section of the boiler:
Figure 2 is a back elevation of the same; and,
Figure 3 is a front elevation of the disc designed to be inserted in the flame-tube.
In the hinder end of the flame-tube g there is inserted a ring a the outer circum-
ference of which is in contact with the inner wall of the flame-tube, and the
central opening, a', of which is of the same area as the free space if over the fire-
bridge d. The ring a may be made of metal or of fire-proof material, but it is
best to construct it of fire clay.
In front of the ring a, in the interior of the flame-tube g, is placed the disc b,
which is best made of cast iron, and is composed of two parts united together, as
shewn in Figure 3. The disc 6 may, however, be equally well constructed of fire-
proof material, or of sheet iron or steel. It is arranged centrally in the flame-tube
at a small distance from the ring a, and is secured in position by means of wedge-
pieces c. A narrow annular space is left free between the 'disc b and the wall of
the flame-tube the area of this space being equal to that of the free space f
over the fire-bridge, and to that of the opening a¹ in the ring a³.
The gases of combustion given off in the grate sweep along the wall of the flame-
tube, become thoroughly intermixed with the air of combustion at the point of
their passage through the opening between the disc b and the flame-tube, and are
then forced together by the ring a. At the point where the contraction occurs, a

page_text: further intimate mixture of the gases of combustion and the air takes place, so
that the gases burn while producing a great heat, and pass into the lateral flues
as pointed flames.
The arrangement described affords the advantage that it is susceptible of appli-
cation without difficulty to Cornish boilers already at work and that it has not the
effect of making the flame-tube less accessible.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is: -
An arrangement of cornish steam boilers for mixing and concentrating the gases
of combustion as they leave the flame-tube consisting of a disc arranged centrally
in the flame tube at the end of the latter, an annular space being left between the
said disc and the flame-tube, and of a ring arranged at a short distance behind the
disc, which ring draws together the gases of combustion which pass through
the space between the disc and the flame-tube substantially as hereinbefore
described..
Dated the 20th
"
J
100%
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicants.