Improvements in Boiler Furnaces and Flues.
Year: 1896

page_text: Date of Application, 25th Aor., 1896
Complete Specification Left, 20th Jan., 1897-Accepted, 27th Mar.. 1897
We, JonN BROWN AND COMPANY LIMITED of Atlas Works, Sheffield in the
County of York, and JOSEPH NODDER, of the same place, Iron Works Manager
do hereby declare the nature of this invention to be as follows:-
This invention has for its object to provide a furnace, or flue, for boilers,
whereby the objectionable strains, which are due to unequal expansion and
contraction, are overcome.
According to this invention the upper portion of the furnace or flue, which is
above the fire-bars, and is therefore subjected to the direct action of the heat of
the fire and products of combustion, is made of corrugated or equivalent form in
longitudinal section whilst the portion which is below the fire-bars is made of plain
form, or parallel to the axis of the furnace or flue. The upper part is preferably
made of somewhat less thickness than the lower plain portion, the former being,
say, for example a half inch in thickness, and the latter being five-eighths of an
inch in thickness, although we do not limit ourselves to these dimensions. The
difference in form between the upper and lower portions of the furnace or flue, and
the difference in thickness will give the requisite protection against unequal
expansion and contraction and consequent objectionable strains. The corrugated,
or equivalently formed upper portion, preferably extends down to, or a little
below, the level of the fire-bare, so that the part which is subjected to direct firo
heat is of the corrugated, or equivalent form, whilst the part below the fire-
bars, which is not so subjected to direct fire heat, is of the aforesaid plain
form.
Dated this 25th den of Anvil 1906
JOHNSONS & WILLCOX,
47 Lincoln's Inn Fields, London, Agents.
Improvements in Boiler Furnaces and Flues.
We, JOHN BROWN AND COMPANY, LIMITED of Atlas Works, Sheffield, in the
County of York, and JOSEPH NODDER, of the same place, Iron Works Manager,
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 has for its object to provide a furnace, or flue, for boilers,
whereby the objectionable' strains, which are due to unequal expansion and
contraction, are overcome. We will refer to the accompanying drawing shewing
a portion of a furnace or flue made in accordance with this invention. Figure 1 is
a longitudinal section and Figure 2 is a cross section. According to this invention
the upper portion A of the furnace, or flue, which is above the fire-bars, and is

page_text: therefore subjected to the direct action of the heat of the fire and products of
combustion, is made of corrugated, or equivalent, form in longitudinal section,
whilst the portion B which is below the fire-bars is made of plain form, or parallel
to the axis of the furnace or flue. The corrugations in the part A are shewn as
being of curves of equal radius but we do not limit ourselves to this form of
corrugations as corrugations or grooves of other form can be made in this part of
the furnace or flue. The upper part A is preferably made of somewhat less
thickness than the lower plain portion B as shewn in the drawing, the upper
part A being, say, for example, a half inch in thickness, and the lower plain
portion B being five-eighths of an inch in thickness, although we do not limit
ourselves to these dimensions.
The difference in form between the upper and lower portions A and B of the
furnace, or flue, will give the requisite protection against unequal expansion and
contraction and consequent objectionable strains and this protection will be
enhanced by the difference in thickness. The corrugated or equivalently formed,
upper portion A preferably extends down to, or a little below, the level of the
fire-bars so that the part which is subjected to direct fire heat is of the corrugated,
or equivalent form, whilst the part below the fire-bars, which is not so subjected to
direct fire hent, is of the aforesaid plain form.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. A boiler furnace or flue having the part which is above the fire-bars of
corrugated or equivalent form in longitudinal section and the portion which is
below the fire-bars plain or parallel to the axis of the furnace or flue.
2. A boiler furnace or flue having the part which is above the fire-bars of
corrugated or equivalent form in longitudinal section and of less thickness than the
portion which is below the fire-bars the latter portion being, plain or parallel to the
axis of the furnace or flue.
Dated this 20th day of January 1897.
JOHNSONS & WILLCOX,
47 Lincoln's Inu Fields, London, W.C., Agents.