IMPROVEMENTS IN AND RELATING TO THE CONSTRUCTION AND HEATING OF STEAM-BOILERS follows
Year: 1884

page_text: "
I, WILLIAM CLARK, of 19 Lee Street, Plumstead, in the County of Kent,
Engineer do hereby declare the nature of said invention for IMPROVEMENTS IN
AND RELATING TO THE CONSTRUCTION AND HEATING OF STEAM-BOILERS
follows:-
"
to be as
My Invention relates chiefly to the novel construction of flue-tubes for steam
boilers whereby they will offer a greater resistance than heretofore to compression
and their heating surface is greatly increased. It also relates to the employment
of apparatus whereby the currents of heated air and gas are retarded and
compelled to remain longer in the flues and around the boiler than heretofore
so that the whole or nearly the whole of the heat generated in the furnace is
utilized.
My improved flue tubes are made in sections, but instead of being of the same
diameter throughout, the alternate sections are made of different diameters that is
to say there is a large section between two small sections and each large section has
extending longitudinally through it, a series of water tubes opening at their ends
just outside of the adjacent small sections and fixed in angle iron rings or plates.
The said water tubes therefore are in connection with, and filled by, the water in
the boiler and the heat currents in the flue act not only upon the surface of the
flue plates but also all around the water tubes the result being an increased
evaporation of the water in the boiler with less consumption of fuel.
In some instances I make the flues in both the large and small sections plain but
for flues of large diameter I form the various sections of the flue tubes with
undulations or corrugations; or I form the flue sections into bulbous or barrel-
shaped figures, that is to say, I first form the sections of plain plates with welded
joints. I then place them in a furnace until the required heat is obtaind and pass
them through a set of rolls which are so constructed as to impart to the plain
circular plates the required bulbous corrugated or other shape leaving a plain or
parallel part at each end to form a lap, rivetted, or other joint. Or if desired the
flue sections may be formed from a bloom or solid piece of iron or other metal
forged and rolled into the required form.
I sometimes provide the flue tubes with a series of plates or shields to retard the
passage of the heat and cause the heated currents to impinge more effectually upon

page_text: the flue plates and water tubes. These shields or plates are mounted on arms or
levers hinged or jointed to eyes or eye bolts fixed in the flue; and they are connected
to a rod or bar extending to the front of the boiler and conveniently arranged for
raising and lowering the said plates or shields.
Instead of allowing the heated currents of the gases and smoke from the furnace
to escape in the usual manner from the flues I provide for keeping them in
circulation through the flues by means of an air propellor or circulator by which
they are caused to return below the furnace and up through the fire grate. The
unconsumed gases thus having to pass up repeatedly through the fire grate are
quickly ignited and greatly increase the heat. A damper or air valve is placed at
the uptake or any convenient part, and another one is placed in front of the
propellor or circulator so as to regulate the admission or passage of air to assist
combustion. With this arrangement I can maintain a slow combustion in the
furnace with great advantage, and in some cases I can work with both dampers
closed, the heated currents being kept in circulation by the propellor without being
allowed to escape from the flues.
DUL
100A
HASELTINE, LAKE & Co.,
For the Applicant.
COMPLETE SPECIFICATION.
I, WILLIAM CLARK, of 19, Lee Street, Plumstead, in the County of Kent,
Engineer do hereby declare the nature of my invention for "IMPROVEMENTS IN
" and in
what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
AND RELATING TO THE CONSTRUCTION AND HEATING OF STEAM-BOILERS
My invention relates chiefly to a novel construction of flue-tubes for steam-
boilers, whereby they offer greater resistance than heretofore to compression and
their heating surface is greatly increased. It also relates to the employment of
apparatus whereby the currents of heated air and gas are retarded and compelled
to remain longer in the flues and around the boiler than heretofore, so that the
whole, or nearly the whole, of the heat generated in the furnace is utilized.
My improved flue-tube is composed of parts of different diameter, which I term
large and small sections, arranged alternately, that is to say, it has a series of large
sections cach of which is placed between two small sections. Each large section
bas, extending longitudinally through it, a series of water-tubes open at their cuds,
which tubes are arranged in a circle, or part of a circle, just outside of the adjacent
small sections, and are fixed in angle iron rings, hoops or plates which unite the
said large and small sections. The said water-tubes, therefore, are in connection
with, and filled by, the water in the boiler, and the heated currents in the fluo
act, not only upon the surface of the flue-plates, but also upon the external
surface of the water-tubes, the result being an increased evaporation of water in
the boiler.
I sometimes provide a series of plates or shields to retard the passage of the
heated air and products of combustion and cause them to impinge more effectually

page_text: upon the flue-plates and water-tubes. These shields or plates are combined with
means whereby they may be conveniently raised and lowered as hereinafter set
forth.
Instead of allowing the heated air and products of combustion to escape in the
usual manner from the flues, I provide for keeping them in circulation through
the same by means of a fan or similar apparatus whereby they are repeatedly
caused to return below the furnace and pass up through the fire-grate, so that
the unconsumed gases, which would otherwise escape, aro utilized to increase the
heat.
My invention is conveniently and advantageously carried into practice in the
manner illustrated in the accompanying drawing, in which
Figure 1 is a longitudinal section of a boiler embodying my improvements.
Figure 2 is a transverse section of the same on the line x, x Figure 1.
Figure 3 is a horizontal section of part of the said boiler.
Figure 4 is a side elevation, partly in section, shewing a slight modification of
my invention.
5
a, a are the large sections, and b, 6 are the small sections of the flue-tubo.
c, c are the water-tubes. These tubes are fixed in the angle-iron rings or plates d,
which unite the sections a and b. The rings or plates d are preferably swaged and
thickened (as shewn at Figure 4) around the apertures in which the tubes are
inserted, in order to form an efficient joint, and prevent leakage, around the said
tubes.
In some instances, I make the tubes or sections a, b plain, straight or parallel, as
shown in Figure 1, but for flues of large diameter I prefer to make them with
undulations or corrugations, or with a bulbous or barrel-shaped configuration, as
shewn in Figure 4, that is to say, I take plates or sheets and first form them into
plain tubes with welded joints. I then heat the tubes in a furnace and pass them
through a set of rolls, which are so constructed as to impart to tho plain circular
tubes the required bulbous, corrugated or other shape, leaving a plain or parallel
part at each end to form a lap-rivetted or other joint. Or, if desired, the flue-
sections may be formed from a bloom or solid piece of iron or other metal forged
and rolled into the required form.
The water-tubes c are not liable to become choked, as the water continually
circulates through them. Moreover any sediment or deposit that may accumulato
therein can be very readily removed, when the interior of the boiler is cleaned.
Although the said tubes are shewn straight, and I prefer to make them so, yet
it is obvious that the same result might be attained by using curved or spirally
formed tubes.
k, kare the plates or shields for retarding the passage through the flue, of the
heated air and products of combustion. These retarding plates or shields are
mounted on arms or levers / hinged or jointed to eyes or eye-bolts m fixed in tho
lower part of the large sections a. The arms or lovers are connected or coupled
by rods or links n; and a rod o is attached to the lever of the plate or shield /
adjacent to the front end of the boiler, by which rod the said plates can be moved
or adjusted. And the rod o has in it a series of notches o¹ to engage with a stud
or projection p which will hold the rod when adjusted. The plates or shields / can,
therefore, be raised and lowered and held in any desired position to regulate the
passage of the heated air and gases through the flue.
q is a fan or blower for propelling or circulating the heated air and gases through
the flue-tube. This fan is arranged within a flue or passage q¹ which extends
beneath the boiler and is connected with the rear end of the flue-tube by means of
the external flues q², q³, and with the front end of the said flue-tube beneath the
fire-grate by means of the pipe g. The fan q is mounted upon a shaft r which is
carried in bearings 8 and is driven by a belt passing around the pulley t.
The said fan draws the heated air and products of combustion from the rear end
of the internal flue-tube and forces them into the front end of the said tube beneath
the furnace, so that they pass through the latter and are again utilized.

page_text: In some cases, I arrange the said fan in any suitable manner to be driven by a
jet of steam or water, instead of by a belt and pulley as above described.
I place a damper or air-valve u in the up-take and another damper or air-valve v
in a pipe v extending laterally from the flue or passage q¹.
By opening the damper u I can permit the escape of the heated air and products
of combustion. And by opening or closing the damper v, I can regulate or control
the admission or passage of air into the said flue or passage to assist the combustion
in the furnace. With this arrangement I can maintain a slow combustion in the
furnace with great advantage, and, in some cases, I can work with both dampers
closed, the heated currents being kept in circulation by the fan without being
allowed to escape from the flues.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:
First. The construction of a flue-tube with large and small parts or sections, and
with water-tubes arranged between the rings, hoops or plates which unite or connect
such sections, substantially as, and for the purposes, set forth.
Second. A steam-boiler constructed with a flue-tube composed of large and
small sections and provided with water-tubes and with retarding plates or shields,
substantially as described with reference to the accompanying drawing, for the
purposes specified.
Third. The combination, with the internal flue-tube, of the external flues and
the air propelling or circulating apparatus, (with or without the dampers), all
substantially as, and for the purposes, set forth.
Dated this 30th day of December 1884.
HASELTINE, LAKE & Co.,
For the Applicant.