Improvements in the Construction of Boiler Flues.
Year: 1890

page_text: Date of Application, 15th Jan., 1890
Complete Specification Left, 3rd July, 1890-Accepted, 9th Aug., 1890
PROVISIONAL SPECIFICATION.
Improvements in the Construction of Boiler Flues.
I BENJAMIN BROWN Grimesthorpe Road, Sheffie'd in the County of York, Boiler
Smith do hereby declare the nature of my invention to be as follows:
: -
This invention relates to a novel construction of the flues of boilers, the chief
object being to increase the strength of same.
I propose therefore to form such flues of a barrel shape, or of a series of such
shapes, in combination with or without circumferential strengthening ribs of the same
continuous material, formed on the internal surface of the flue plates.
1 propose that the said ribs or belts shall for example be wave shaped undulations
of the same thickness as the thickness of the plate, thus in a plate 3" thick, the
thickness of the plate and rib or belt would be " through the centre.
I do not bind myself to the diametrical proportions of the ends and centre of the
flue relatively, nor to the number of ribs or belts, as these may be varied.
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"
ROBT. F. DRURY, Fel. Inst. P.A.,
Bank Buildings, George Street, Sheffield, Agent for Applicant.
COMPLETE SPECIFICATION.
Improvements in the Construction of Boiler Flues.
I, BENJAMIN BROWN Grimesthorpe Road, Sheffield, in the County of York, Boiler
Smith 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 a novel construction of the flues of boilers, such as are
used for generating steam for stationary and other steam engines, the object being to
increase the strength, and the heating surface.
I therefore purpose in the first place to form the said flues of what may be termed
a barrel shape, or gradually increasing in diameter from both ends to the centre, or
of a series of such barrel shaped lengths, and 1 strengthen such lengths of flue,
by forming circumferential ribs from the same continuous material on the internal
surface.
I have illustrated my invention in the annexed sheet of drawings, in which:
Fig. 1, is a section (made longitudinally) of á flue, made according to my
invention.
inch plates.
inch plates.
Fig. 2, is a section of a full size 2 inch rib for
Fig. 3, is a section of a full size 3 inch rib for
In carrying out the invention I form upon the internal surface of the flue A or
upon the surface of the plate that is intended to form the flue and from the same con-
tinuous metal a series of solid ribs or belts B, so that when the plate is curved
round to the desired shape, the said ribs or belts shall form a series of circumferential
rings upon the inner face thereof, giving great additional strength to the flue, and
increases the heating surface.
I make the flue of a bellied form or barrel shaped, that is increasing in diameter
from the ends to the centre such as shown in Fig. 1, which form also greatly
increases its power to prevent collapse, but 1 may apply my solid strengthening ribs
or belts to parallel flues if desired.
I prefer to make the ribs or belts of a segmental sectional form, or of a waved
shape, such as shown in Fig. 2, but I may vary them in their proportions, as shown
in Fig. 3. In practice I propose for example to make the centre of a 6 foot flue to be

page_text: about one and a half inches larger than the ends and the extra depth of the rib to be
the same as the thickness of the plate, thus if the plate is of an inch thick, its
thickness through the rib will be of an inch. I should make the breadth of such a
rib 2 inches, and the distance from centre to centre of each rib 10 inches or
thereabouts.
I wish it to be understood that I do not bind myself to the amount of curve or
diametrical proportions of the ends and centre of such barrel shaped flues, nor to the
size, form, or number of the ribs or belts as it is evident that these may be varied.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what I
claim is :-
1-A cylindrical boiler flue having a number of internal circumferential
strengthening ribs or belts, formed upon the face of the plate, and from the same
continuous metal; substantially as hereinbefore described and as illustrated.
2-A boiler flue increasing in diameter from the ends towards the centre, (or
bellied,") and having a number of internal circumferential ribs or belts, formed
upon the face of the plate, and from the same continuous metal, substantially as
herein before described and shown in Fig. 1 of the drawings.
Dated the 2nd day of July 1890.
ROBERT F. DRURY, Fel. Inst. P.A.,
Bank Buildings, George Street, Sheffield, Agent for Applicant.