Improvements in Steam Boiler Flues, Fire Boxes, and Tubes.
Year: 1891

page_text: Date of Application, 4th Sept., 1891-Accepted, 10th Oct., 1891
COMPLETE SPECIFICATION.
Improvements in Steam Boiler Flues, Fire Boxes, and Tubes.
WILLIAM EDWARD CORRIGALL of 27 Sterndale Road, West Kensington
Park, W., 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 :-
The furnace (on Sheet 1 Fig. 1 scale 12th) consists of a series of hollow
truncated cones increasing in depth and length towards the throat, by this means
the heating surface is disposed to intercept the heated gases as they are given off
from the burning fuel and as the area towards the throat is slightly diminished by
the increasing depth of the cones these gases are more intimately mixed with the
air supplied for their combustion so that on escaping into the combustion chamber
the combustion is more thorough and complete than by any other means.
I also arrange the furnace without increasing the depth of the cones so as to
obtain the advantages of the disposition of the heating surface without the contraction
at the throat although this does not give all the advantages of the complete
arrangement.
Sheet 2 shows full sized sections of the first and last corrugation of the furnace,
the first Fig. 2 being that next the mouth of the furnace the last Fig. 3 being
next the throat the other corrugations are arranged so that the lengths of the
cones A the depths of the cones B gradually increase from those shown in Fig. 2
to those shown in Fig. 3, the angles of the cones D and E being retained
approximately constant for all the cones the initial sizes of A. and B and the
radius of the curves C I determine according to the thickness of the plates and
the pressure they have to resist. The line H. L. shows the outer line of the
furnace corrugations.
In order to extract from the heated gases the maximum amount of heat I arrange
my tubes so that the upper portion of each tube has longitudinal outwardly
projecting ribs forming heating surface in contact with the water, 30% greater
than the ordinary tubes these ribs extend the whole length of the tube excepting a
small portion at the ends where I retain the ordinary circular section to facilitate
the fixing of the tubes in the tube plate for which purpose any of the ordinary
methods in general use may be adopted.
Sheet 3 Fig. 4 shows a full sized longitudinal section of the tube the centre
portion being omitted from the drawing for convenience of length, Fig. 5 shows
that portion of the tube to fit the holes in the tube plate, Fig. 6 is a section of
the tube at the centre showing the form and distribution of the heat ribs.
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 I do not
claim broadly the constructing of a corrugated flue or fire box but what I do
claim is
The manufacture of corrugated steam boiler flues or fire boxes in which the
outwardly projecting corrugations and the inwardly projecting corrugations are
arranged.
(1) As truncated cones increasing in length with or without increasing in depth
from furnace mouth to throat as represented on Figs. 1, 2, and 3 of the drawings
hereunto annexed.

page_text: (2) The arrangement on the tubes of longitudinal heat ribs as represented on
Figs. 4, 5, and 6.
(3) The use of either (1) or (2) separately or together.
Dated this 4th day of September 189г.
W. E. CORRIGALL,
27, Sterndale Road, West Kensington Park, London, W.