Improvements in or connected with Steam Generators.
Year: 1898

page_text: Date of Application, 16th Apr., 1898
Complete Specification Left, 16th Feb., 1899-Accepted, 18th Mar., 1899
Date of Application, 16th Apr., 1898
Complete Specification Left, 16th Feb., 1899-Accepted, 18th Mar., 1899
PROVISIONAL SPECIFICATION.
Improvements in or connected with Steam Generators.
We, WILLIAM ROBERT CALDWELL, Agent, of 7, Claremont Place, and JAMES
KENNEDY, Engineman, of 230, Pilgrim Street, both in the City and County of
Newcastle-on-Tyne, do hereby declare the nature of this invention to be as
follows:-
Our invention relates to steam generators of the kind having internal flues such
as those of the Lancashire and Cornish type. It is the object of this invention
to provide an apparatus for use with, or so construct, the flue internally that the
heated gases from the furnace are brought into more efficient contact with the
beating surfaces before leaving the flue than in flues as at present constructed
and arranged.
According to our invention we provide the flue with two or more longitudinal
partitions or divisions so disposed in a parallel, diverging or other manner as to
divide the flue into three or more longitudinal chambers or flues, arranged in such
manner in regard to the furnace (which may be of the full width of the flue as
usual), that the products of combustion first pass over the bridge and through one
or more chambers to the end of the flue, through an aperture into and back
through one or more of the side chambers to the interior of the bridge (which is
enlarged and elongated for the purpose) and from thence through the third or
other chambers and out to the external flue.
We will now describe such a construction and arrangement of flue. The portion
of the flue where the grate is disposed is or may be of the usual construction and
the bridge is of the usual or convenient height, beyond the bridge the flue is
divided into three chambers by means of two longitudinal partitions of curved,
flat or other convenient form and whose upper part terminates at or about the
level of the bridge, their bases being nearer together than their upper part so that
a recess or chamber of more or less trough shaped form is centrally disposed below
the level of the bridge and beneath that part through which the products of com-
bustion pass so that the dust and ashes passing over the bridge may collect therein
and from which they may be readily removed when the flue is cleaned.
At the rear end of the first mentioned chamber the products of combustion
pass by an aperture into one of the side chambers formed between the curved or
flat partitions and the sides of the flue, after passing through which they enter a
chamber formed in the bridge which is enlarged and elongated for the purpose,
from thence they pass into and through the other side chamber and out into
the external flue by an aperture in the end which is formed or built up so as to
close the ends of the two first mentioned chambers.
The partitions or divisions may be formed of firebrick, fireclay tiles or other
suitable material and they are or may be supported and strengthened by through
or cross bolts, or tie rods conveniently arranged, and bridge pieces may be disposed
across the trough shaped chamber referred to; the base of the latter is formed by
the flue itself or of similar material to the partitions as also may be the partially

page_text: closed end of the flue and the hollow bridge. The whole internal construction
may be built in the flue or formed in sections for easy removal and the partially
closed back end and firebridge may be formed with removable parts or doors for
cleaning or inspection purposes, or the closed end may have an aperture or per-
forations closed by a damper or the like so that in case of any defects occasioning
a stoppage of the flues or chambers the damper may be removed and a through
draught obtained from the first chamber into the external flue.
It will thus be seen that the products of combustion pass through the flue in
such manner as to be always in close contact with the top and sides thereof instead
of the greater portion passing through the centre as in flues as usually constructed,
so that a large percentage of heat is absorbed before the products of combustion
leave the interior of the flue thus tending to a greater economy of fuel and general
increase of efficiency whilst the trough shaped chamber being adapted to receive
and hold a large quantity of dust and ashes cleaning may be deferred for long
periods.
1
11
PRYOR & HARVEY,
Agents.
Improvements in or connected with Steam Generators.
We, WILLIAM ROBERT CALDWELL, Agent, of 7, Claremont Place, and JAMES
KENNEDY, Engineman, of 230, Pilgrim Street, both in the City and County of
Newcastle-on-Tyne, 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:-
Our invention relates to steam generators of the kind having internal flues such
as those of the Lancashire and Cornish type. It is the object of this invention
to provide an apparatus or appliance, for use with, or so construct the flue inter-
nally that the heated gases from the furnaces are brought into more efficient
contact with the heating surfaces before leaving the flue than in flues as at present
constructed and arranged.
According to our invention we provide the flue with two or more longitudinal
partitions or divisions so disposed in a parallel, diverging or other manner as to
divide the flue into three or more longitudinal chambers or flues arranged in such
manner in regard to the furnace (which may be of the full width as usual)
that the products of combustion first pass over the bridge and through one
or more chambers to the end of the flue, through an aperture into and back
through one or more of the side chambers to the interior of the bridge (which is
enlarged and elongated for the purpose) or a space thereat and from thence
through the third or other chambers and out to the external flue.
We will describe our invention in reference to the accompanying draw-
ings in which Fig. 1 is a longitudinal section and Fig. 2 a plan mostly in section
of a Lancashire boiler having our invention applied to the flues; in each of these
figures, the section of the shell is taken on its centre line and the sections of the
flues on their centre lines. Fig. 3 is a transverse section, the left half being on
the line 1-2 and the other on the line 3-4 in Fig. 1. Fig. 4 is an end elevation
at the rear of the boiler. Fig. 5 is a longitudinal elevation illustrating the
application of the invention to flues or fire tubes of small diameter. Figs. G
and are respectively cross sections on lines 5-6 and 7-8 in Fig. 5 looking to
the left and right. In Figs. 1 to 4 inclusive, the ordinary setting is indicated

page_text: by dot and dash lines as is also the wall of the tube in the other figures while
the direction in which the gases travel is shown by arrows in Figs. 1, 2 and 5.
Referring first to Figs. 1, 2, 3 and 4, a, a are the internal flues of the boiler A
set with external flues a¹, al as usual. Taking one flue of the boiler (both are
of course alike) the furnace b, or the portion of the flue where the grate bis
disposed, is or may be of the customary construction and the bridge c is of the
ordinary or convenient height. Beyond the bridge c, the flue a is divided into
three chambers d, d¹ and d by means of two longitudinal partitions e, el curved
as shown or they may be flat or of other suitable form. The rear ends of the
chambers d, d¹ are suitably closed, but that of the chamber d³ is not, as will be
presently explained. The upper parts e², e2 of the partitions terminate at or
about the level of the bridge c and their bases e³, e³ are nearer together than the
said parts so that a recess or chamber f of a more or less trough-shape is obtained
centrally below the level of the bridge c and at the bottom of the chamber d
through which the products of combustion pass as they leave the furnace b;
thus the dust and ashes passing over the bridge c may collect in the chamber f
wherefrom they can be readily moved when the flue is cleaned. At the rear of
the chamber d, the products of combustion pass by an aperture 9 in the parti-
tion e into the side chamber d (formed as described between the partition e and
the side of the flue a) through which they return to the front of the boiler to
enter a chamber or space constituted either by an extension of the bridge c or,
as represented in Figs. 1 and 2 at eat the back of same, the mouth of the
chamber being closed by the plate e and the roof of the chamber or space
formed by the plate resting on the top of the bridge and the plate e. From
this chamber c¹ the products of combustion pass into and through the other side
chamber d2 and out into the external flue a¹ by an aperture i in the plate e6
closing the ends of chambers d, d¹; the ends of the latter chambers may of course
be otherwise covered or built up.
The partitions or divisions e, e¹ are illustrated as made of plates of iron or
steel but they may be formed of firebrick or fireclay tiles or other suitable
material and built in the flue or formed in sections for easy removal or adapted
to be removed whole as shown in the drawings. When the partitions e, el are of
iron or steel they are or may be provided with projecting ledges, as indicated
on the partition e at the right hand side of Fig. 3, for receiving and holding a
protective covering of fireclay or similar refractory material. Also, as will be
obvious, removable parts or doors are or may be fitted at the plate e and
the firebridge c for cleaning or inspection or the closed end may have an aperture
or perforation closed by a damper or the like so that in case of any defects occa-
sioning a stoppage of the flues or chambers the damper may be removed and a
through draught obtained from the first chamber into the external flues a¹, a¹.
Referring to Figs. 5, 6 and 7 which exemplify the application of the inven-
tion to flues or fire tubes of small diameter, k is a Y shaped core or plate
adapted for insertion within and passing from end to end, or for a portion of the
length, of the tube and dividing the latter into the chambers d, d', d² and having
cut away parts or apertures at m, m³ for passage of the gases from chamber to
chamber and a segmental end piece o for closing the ends of chambers d, d¹ and
a similar part o¹ for closing the other ends of chambers d', d².
In this arrangement the action is similar to that before described, the gases
passing first into the chamber d by opening p, then by aperture m io chamber d¹,
next by aperture m' to chamber wherefrom they pass out into the ordinary
flue by the opening p¹.
It will thus be seen that the products of combustion pass through the flue in
such manner as to be always in close contact with the whole area thereof instead
of the greater portion passing through the centre as heretofore so that a large
percentage of heat is absorbed before the products of combustion leave the interior
of the fue thus tending to a greater economy of fuel and general increase of

page_text: efficiency whilst in large flues the trough-shaped chamber receives and holds a
large quantity of dust and ashes so that cleaning may be deferred for long periods.
The invention is readily applicable to existing flues there being practically
no alteration in the construction except by the addition of parts which can be
readily fixed at a small expense without disturbance of the setting and in the
application to fire tubes the dividing cores can be readily inserted from either
the front or back end of the boiler.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what
we claim is: -
'
1. The improvements in steam generators consisting in providing the flue or
fire tube with two or more longitudinal partitions or divisions so disposed in a
parallel, diverging or other manner as to divide the flue or tube into three or
more longitudinal chambers or flues having connecting apertures and closed parts
so arranged as to direct the products of combustion through the chambers, sub-
stantially as set forth.
2. For use in fire tubes or flues of small diameter, a core such as k of Y or
other suitable form in cross section adapted to divide the flue into three or more
chambers and having end parts o and o¹ for closing the ends of two or more of
the chambers and cut away parts or apertures in, m³ all arranged so as to direct
the products of combustion in the manner described, substantially as set forth.
3. In steam generators, the improved flue, or appliance for use with a flue,
constructed, arranged and adapted to operate, substantially as herein described
and shown in Figs. 1, 2, 3 and 4 of the accompanying drawings.
4. In steam generators, the improved flue or fire tube, or appliance for use
with a flue or fire tube, constructed, arranged and adapted to operate, substan-
tially as herein described and shown in Figs. 5, 6 and 7 of the accompanying
drawings.