Improvements in Internal Furnace Flues for Boilers and the like.
Year: 1894

page_text: This Print is in accordance with the Original Specification as it stands after
?
Amendment (under Section 18 of the Patents, &c. Act, 1883), as allowed by
the decision of the Comptroller General of the 16th day of April 1896.
PROVISIONAL SPECIFICATION.
Improvements in Internal Furnace Flues for Boilers and the like.
I, HENRY CROMPTON ASHLIN of Oriel Chambers, 14 Water Street, Liverpool,
in the County of Lancaster, Consulting Engineer, do hereby declare the nature
of this invention to be as follows:-
This invention relates to furnace tubes a section of which would show them to be
formed in reversed arches, the hollow of one set of arches being turned to the outer
or water side of the furnace and the hollow of the other or reversed set of arches
being turned to the inner or fire side of the furnace and so arranged that the ends
of the outer arches on the water side of the furnace come directly above the centre
of the reversed or inner arches of the furnace side, the centres of the outer
arches in turn coming directly above the ends of the reversed or inner arches.
Consequently each arch is supporting its neighbour and strengthens it in its
weakest part and at the same time maintains a continuous straight line of metal
running between the arches and from one end of the furnace to the other and so
avoiding what is known as the bellowsing action of the corrugated furnace and by so
making a rigid stay of the furnace avoiding as far as possible the through stays to
the front of the boiler for the purpose of counteracting this bellowsing action.
Each arch may if desired be strengthened more particularly upon the outer or
water side by the addition of a circumferential rib at the junction of or end of each
arch, the inner or fire side of the furnace would have the arches coming to an
obtuse angle or rounded whilst the outer could either come to an obtuse angle or
be rounded or may be provided with strengthening ribs or each alternate arch may
have the ribs.
By this arrangement of the furnaces the arches or uneven surfaces exposed to
the flame inside the furnaces are smaller than those in the ordinary patent furnaces
whilst the surfaces upon the outer or water side of the furnace do not expose
hollows sufficient to unduly gather salt or other deposit.
Dated this 1st day of November 1894.
W. P. THOMPSON & BOULT,
Agents for the Applicant.

page_text: Improvements in Internal Furnace Flues for Boilers and the like.
I, HENRY CROMPTON ASHLIN, of Oriel Chambers, 14 Water Street, Liverpool,
in the County of Lancaster, Consulting 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 :-
This invention relates to furnace tubes for steam generators.
The accompanying drawing shows a longitudinal section through one of the
improved tubes the central portion of the tube being for convenience broken
away.
The wall of the furnace tube as clearly shown in the drawing is so formed that
when viewed in section it has the appearance of reversed "arches."
"
The "arches" on the inside and outside of the tube are so formed relatively to
one another as to break joint, that is to say those on the outside A B C, C D E
have their hollows or concavities B D opposite to the ends F G of the "arches"
formed on the inside of the tube, the concavities H J K of the "arches
on the
inside of the tube being consequently opposite to the ends A CE of the "arches"
on the outside of the tube.
"
Thus the "arches on the inside support those on the outside.
"
"
The arrangement moreover of the internal and external "arches" is such that a
continuous straight line or belt of metal, shown by the dotted lines L M runs
between the "arches from one end of the furnace to the other; thus making
a rigid stay of the furnace itself, and by avoiding the so-called "bellowsing
action of the ordinary corrugated furnace obviating to a large extent the use of the
through stays to the front of the boiler which are usually employed for the purpose
of counteracting this "bellowsing " action.
By the arrangement of the furnace tube described above and illustrated in the
drawing the "arches" or irregularities exposed to the flame inside the tube are less
pronounced than those in the ordinary corrugated furnaces, whilst the surfaces
upon the outer or water side of the tube do not expose hollows sufficient to unduly
accumulate salt or other deposit. The "arches may have any suitable concavity
as. shown by way of example in dotted lines in the drawing and may be of any
desired length.
The arrangement of the reversed arches shown in the drawing can be varied by
making the positions of the inner and outer arches correspond so that the junction
point of two arches upon the outside would correspond with the junction point of
two arches upon the inside, but this arrangement I do not consider so good as that
shown in the drawing, and I merely indicate it as a possible modification.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is ;-
1. A furnace tube the walls of which are arranged in reversed "arches"
substantially as described.
2. A furnace tube the walls of which are arranged in reversed "arches" spaced
alternately so that the "arches" in the interior "break joint" with those upon the
exterior substantially as described and illustrated in the accompanying drawing;
3. A furnace tube the walls of which are arranged in reversed "arches with
a continuous straight line or belt of metal such as L M running from end to end of
the tube substantially as and for the purpose described.

page_text: 4. A furnace tube for steam generators constructed substantially as and for the
purpose described and illustrated in the accompanying drawing.
Dated this 21st day of August 1895.
HENRY CROMPTON ASHLIN.
Boult & Wade,
Agents for the Applicant.