Improvements in or relating to the Flue Tubes and Fire-boxes of Steam Boilers.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in or relating to the Flue Tubes and Fire-boxes of
Steam Boilers.
ISRAEL MORRIS, Deepfields, Bilston, County of Stafford, Engineer, do hereby
declare the nature of this invention to be as follows:-
The object of this invention is to secure or obtain, to a useful degree, an
increase in the steam generating power in such boiler tubes and an economy
in the use of fuel.
These objects I propose to obtain in the following manner.
I propose to make, of cast iron, fire clay, or other suitable material, a central
shaft, with large screw worm, or screw vane attached.
The shaft shall be hollowed to lighten its weight, and other convenience, and
may be about four to six inches diameter, but the screw vane upon it shall be
extended in diameter to very nearly the same diameter as the boiler flue in
which it is to be used.
The body or wall of the screw vane, may be about one inch thickness, and the
placement of it upon the shaft, shall extend in each circuit round the shaft, to
a length along the shaft of about three feet, if for use in a three feet tube--and
this proportion may rule in other diameters of flue tube.
I propose to use two screw vanes on the shaft, and the heat current will be
conducted in a circular, but advanceing course in the space provided between the
screw vanes in its passage through the flue tube.
This shaft and screw vane shall be placed and used in the boiler flue tube,
and its office is to intercept conduct, and apply in a concentrated form, the
heat current upon the flue plate surface.
It may be found convenient to apply the screw current to half or perhaps
to two thirds of the total length of the flue tube, but, it must not be fixed too
near the bridge.
For convenience I propose to make my screw shaft and vanes in short sections,
as being so will be more conveniently portable.
In the case of vertical flue in vertical boiler, the screw vanes may be con-
structed, and the screw current produced and effected without the use of a central
shaft, a cylinder may be used instead, with the screw vanes attached.
Vertical boilers being comparatively short in height the passage space must
be limited, and so, as a part of this invention, and to prevent the non-combus-
tion of gases, I introduce heated air at an advanced stage in the ascent of the
heat current in any such boiler flue.
Dated the 17th day of October 1898.

page_text: Improvements in or relating to the Flue Tubes and Fire-boxes of
Steam Boilers.
I, ISRAEL MORRIS, of Deepfields, Bilston, in the County of Stafford, 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 improvements in or relating to the flue tubes of
steam boilers, the object being to increase the steam generating power of both
horizontal and vertical boilers and at the same time effect an economy in fuel.
As applied to boilers of both the Lancashire and Cornish types and vertical
boilers my invention consists essentially in means for giving the gaseous products
of combustion a sinuous or screw like path as they pass from the fire so that
the pillar-like current common in most boilers to-day is split up, as it were, into
one or more sheets of current, the bulk of the gases composing which come in
contact with the flue plates.
My invention will be fully described with reference to the accompanying
drawings in which;
Fig. is a longitudinal section of a Cornish boiler, with my improvements
applied,
Fig. 2 a cross section of same and
Fig. 3 a partial vertical section of a vertical boiler.
In carrying out my invention and referring more particularly to Figs. 1 and 2,
a is the shell of the boiler b the flue, e the fire bars and d the bridge. Inside
the flue I place a screw which may be made of any suitable material such as
cast or wrought iron, steel, or fireclay. The screw may have one or more
threads or vanes e of any suitable pitch and preferably extends from the rear
end of the flue to say half or two thirds the distance between that end and the
bridge, though its inner end may be nearer to the bridge; but not so near that
the flames will impinge upon it. The vanes may be of a suitable thickness to
withstand the effects of the heated gases upon them without undue deterioration
and are of a diameter to nearly fill the flue tube. They may be formed integral
with a central shaft or hollow tube or be built up in lengths upon it; but I
prefer to make the screw in short sections as shown, each section being con-
nected to the other so as to form a continuous screw either by being put butt
one against the other or preferably connected together by a socket joint. Such
a joint is shown in Fig. 1 in section, f being a squared end fitting in a corre-
spondingly shaped socket g. When made in this form the sections may be easily
placed in position or removed as may be required. In the illustration, the screw
is formed with two threads or vanes; but, as before indicated, I do not confine
myself to the number of threads or to the particular pitch of same as these may be
varied to suit circumstances.
By the means described the heated products of combustion are conducted
through the flue tube in a sinuous or screw like course, or courses, the length of
which is much greater than the flue tube itself. The advantage of this arrange-
ment is that the gases are enabled to impinge upon the whole interior surface
of the flue tube, giving up their heat to the latter in much greater proportion
than is the case where the gases pass through the tube in a straight pillar-like
form, or a form which only departs slightly from that by being broken up by
cross tubes, and wherein only the outer envelope of gases comes in contact with
the plates. In other words the heat is concentrated on the plates of the flue both
more directly and for a longer period.

page_text: Although in Figs. 1 and 2 I have only indicated the improvements applied
to a Cornish boiler they may be applied to Lancashire boilers or to such that have
more than one flue tube.
In Fig. 3 my improvements are shown applied to a simple vertical boiler in
which a is the shell and h the passage to the chimney which is preferably made
of such a diameter that a man can get through. In this case the screw may be
made up of sections as before; but I prefer to make the sections hollow in the
centre and to support them upon a plate j carried by two cross tubes & placed
just above the fire. This centre part may then be filled with a non-conducting
material. The periphery of the vanes nearly touch the interior shell of the
boiler as described with reference to the flue in Figs. 1 and 2. Instead of the
screws being composed of sections of metal they may be in the form of fire
bricks, formed either in rings or rings composed of separate bricks. The use of
the said cross tubes for the purpose named in vertical boilers, is a special feature
in connection with this invention, and they form a permanent and useful
carriage or bearing, on which to erect the apparatus. Access to the upper
portion of the fire box, above the cross tubes must be through chimney passage
which passes through the steam space as usual, and is of large diameter as already
described.
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 what I
claim is:-
1. In steam boilers of the Lancashire, Cornish or similar types the use of a
continuous screw in the flue tube substantially as and for the purposes described.
2. In steam boilers of the Lancashire, Cornish or similar types, the combination
with the flue tubes, of a screw formed with one or more vanes such as e, said
screw being formed in one continuous piece or built up in sections substantially
as described.
3. In steam boilers of the vertical type the use of a continuous screw in the
combustion chamber substantially as and for the purposes described.
4. In vertical boilers such as referred to the combination of a screw built up
in continuous form or in sections, a hollow chamber such as filled with non-
conducting material, plate and cross tubes k for supporting the superstructure
substantially as and for the purposes described.
5. In steam boilers of the types described the improved means for conducting
the heated gases along the flue tubes or combustion chamber substantially as
described and shown either with reference to Figs. 1 and 2 or Fig. 3 of the accom-
panying drawings and for the purposes set forth.
1000
WILLIAM H. TAYLOR,
Swan Chambers, 69, Market Street, Manchester,
Agent for the Applicant.
WILLIAM H. TAYLOR,
Swan Chambers, 69, Market Street, Manchester,
Agent for the Applicant.