Improvements in or connected with Steam Boilers with Internal Furnaces.
Year: 1894

page_text: Date of Application, 23rd June, 1894
Complete Specification Left, 23rd Mar., 1895-Accepted, 4th May, 1895
PROVISIONAL SPECIFICATION.
Improvements in or connected with Steam Boilers with Internal
Furnaces.
1, JAMES YATE JOHNSON of 47 Lincoln's Inn Fields in the County of
London, Gentleman do hereby declare the nature of this invention (which has been
communicated to me from abroad by Jean Pierre Serve of 17 Quai de Cuire,
Lyons, (Rhone) in the Republic of France Engineer) to be as follows:-
This invention relates to improvements in or connected with steam boilers with
internal furnaces fed with air by mechanical appliances for the purpose of rendering
the combustion more active than it is with the ordinary chimney draught.
The object of this invention is to afford effective protection for those parts of the
said steam boilers which are exposed to the direct action of the fire, and thereby
to avoid the serious deteriorations, which frequently occur in the furnace walls, in
consequence of the very high temperature developed in the furnace.
The invention consists in fitting the surface above the grate with a series of
tubes or passages preferably of small diameter, wherein, by means of a pump,
water is caused to circulate with sufficient speed or activity to prevent it from
being converted into steam as it passes through the said tubes or passages.
The part of the furnace which is situated above the grate may be fitted with a con-
tinuous series of circulation tubes or pipes, arranged in pairs, each pair being formel
by one pipe curved so as to form two arms or branches. The two free ends of each
pair of pipes pass through the month of the boiler furnace which serves as a support
for them, and join circulating devices hereinafter described the bent portion of each
pair of tubes being situated within a block or casting of metal such as iron or steel,
and having the shape of an arch or key-stone, so that by placing a number of such
blocks or castings in juxtaposition an arch is formed, which is capable of supporting
or retaining in place the rear portions of the tubes at the bark of the furnace.
To impart greater strength to the structure, the said blocks or key-stones are each
provided with a projecting pin or stud adapted to enter an eye screwed for the
purpose into the boiler plate.
It will be understood that the pipes may, if desired, have additional supports
provided for them at certain points throughout their lengths, there being formed at
those points cast key-stones integral with them but resembling in shape those
above referred to which constitute the arch, or metal rings may be fitted to them
and secured by means of bolts to the furnace plates.
The first pairs of tubes arranged above the grate, are entirely embedded in
castings and by superposing a series of such castings, solid walls are formed for the
water to circulate in, while they are inaccessible to scales or slag.
In order to produce, in the said pipes, a sufficiently active circulation of wate.
to prevent any steam being generated therein the free ends of each pair of pipes
are connected by means of pipes with two receivers arranged on the front surface of
the boiler or at any other other convenient part.
One of these receivers, receives from a powerful pump, a supply of water drawn
from the lower part of the boiler, whilst the other receiver, communicates with
the upper part of the said boiler.
The intermediate or junction pipes, at the points where they enter the said
receivers are fitted with valves which may be maintained in a raised position by

page_text: springs the power of which is only sufficient to retain them in that position so long
as the operation of the whole arrangement is normal.
It will be understood therefore, that if any one of the pipes should happen to be
burnt or broken, the high pressure of the water in the receivers will cause the
said valves, corresponding to the damaged pipe, to be closed instantly, so that
that pipe shall be isolated from the rest, while the circulation uninterruptedly
continues in all the other pipes.
Each of the connecting pipes may also, be provided with a valve or cock enabling
the attendant completely to isolate the injured pair of pipes which will soon melt
and be finally destroyed by the intense heat prevailing in the furnace.
If the circulation pump happens to discontinue its operation it is important that
there should be formed in the pipes, a sufficient circulation of water to prevent
their being deteriorated until the pump resumes its normal operation.
To attain this result there is fitted to the nozzle of the receiver at which the water
first arrives from the pump a species of valve-chest which receives a pipe leading
from the circulation pump while another pipe commeets the said chest with the lower
part of the boiler direct. The orifices of these two pipes are provided with valves
connected in such a umnner that when one of the valves is closed, the other is open,
care being taken, moreover, that the valve of the water supply pipe is heavier than
the valve of the water discharge pipe.
Hence it will be understood that whenever it should happen that the pump stops
operating the valve of the water supply pipe being the heavier one of the two, will
immediately descend upon its seat, while the other valve being raised the boiler
water will freely he admitted through the pipe which it controls and be allowed
to pass through the circulation tulies owing to the water being by that time
superheated in which case steam bubbles may form in the water, the density of
the water being diminished in consequence. But the moment the pump starts
working afresh the water forced back by its netion will raise the heavier of the
two valves and close the other valve of the pipe communicating with the lower
part of the boiler, thereby restoring the compulsory circulation of water through
the apparatus.
The pivot of the lever connecting the two valves may carry outside of the valve
case, an index pin or style which indicates the relative positions of the said
valves, and thereby enables it to be ascertained whether the pump operates satis-
factorily or not so that the attendant is in a position, if necessary, to displace or
readjust the said valves by hand.
1 do not limit myself to the precise details described as any equivalent arrange-
ment may be employed for the attainment of the same purpose.
When the gases issuing from the furnace are to circulate in lower flues before
entering the boiler tubes as provided for in the Specification of the application for
Letters Patent of the 1st December 1893 No. 23122 the circulation pipe should
be extended beyond the furnace within the combustion chamber and in that part
each pair of pipes will be embedded in a casing which may be of cast iron or steel
having the shape of a key-stone and forming in conjunction with the others, the
whole or part of the arch necessary for guiding the hot gases in the desired
direction.
The means described for carrying out this invention may of course he varied for
example the circulation tubes or pipes may be provided with east steel casings or
jackets throughout their lengths so as to form a kind of longitudinal rib ensuring
sufficient rigidity to obviate the necessity for any intermediate supports for the said
tubes or pipes.
Dated this 23rd day of June 1894.
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.

page_text: COMPLETE SPECIFICATION.
Improvements in or connected with Steam Boilers with Internal
Furnaces.
I JAMES YATE Joussos of 47 Lincoln's Inn Fields, in the County of London,
Gentleman, do hereby declare the nature of this invention (which has been
communicated to me from abroad by Jean Pierre Serve of 17 Quai de Cuire,
Lyons (hone) in the Republic of France Engineer) 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 connected with steam boilers with
internal furnaces fed with air by mechanical appliances for the purpose of
rendering the combustion more active than it is with the ordinary chimney
|dranght.
The object of this invention is to afford effective protection for those parts of
the said steam boilers, which are exposed to the direct action of the fire, and thereby
to avoid the serious deteriorations which frequently occur in the furnace walls in
consequence of the very high temperature developed in the furnace.
The invention consists in fitting the surface above the grate with a series of
tubes or passages preferably of small diameter, wherein by means of a pump or
like apparatus water is caused to circulate or pass with sufficient speed or activity
to prevent it from being converted into steam as it passes through the said tubes
or passages.
I will describe the invention with reference to the accompanying drawings in
which:
Figure is a vertical longitudinal section shewing a steam boiler furnace provided
with this invention.
Figure 2 is a part front view and part cross section of the same.
Fig. 3 shews
a detached view of one of the tubes for the circulation of the water and Fig. 4
shews in longitudinal section a modification in which the water circulating tubes
are extended into the combustion chamber.
A is the internal furnace of a steam boiler,
B is the grate,
C is the bridge and
Dis the combustion chamber.
The part of the furnace A, Figures 1 and 2, which is situated above the grate B,
is fitted with a continuous series of circulation tubes or pipes, arranged in what
may be regarded as pairs, each pair being formed by one pipe a curved so as to
form two arms or branches as shewn in Figure 3. The two free ends of each pair
of pipes pass through the mouth of the boiler furnace which serves as a support
for them, and join circulating devices hereinafter described; the bent portion of
each pair of tubes being situated within a block or casting, of metal such as iron
or steel, and having the shape of an arch or key-stone, so that by placing a number
of such blocks or castings in juxtaposition an arch is formed, which is capable of
supporting or retaining in place the rear portions of the tubes a at the back of
the furnace. To impart greater strength to the structure, the said blocks or
key-stones, are each provided with a projecting pin or stud adapted to enter an
eye c screwed for the purpose into the boiler plate.
It will be understood that the pipes a may, if desired, have additional supports
provided for them at points throughout their lengths, there being formed at these
points cast key-stones integral with them but resembling in shape those above
referred to which constitute the arch; or, metal rings may be fitted to them
and secured by means of bolts to the furnace plates.

page_text: The first pairs of tubes a, arranged above the grate B, are entirely embedded
in castings d, and by superposing a series of such castings solid walls are formed
for the water to circulate in, while they are inaccessible to scale or slag.
In order to produce in the said pipes a a sufficiently active circulation of water
to prevent any steam being generated therein, the free ends of each pair of pipes
are connected by means of pipes a' a² with two receivers E E7 arranged on the
front surface of the boiler or at any other convenient part.
One of these receivers E, receives from a powerful pump or equivalent forcing
apparatus a supply of water which may be drawn from the lower part of the
boiler, whilst the other receiver E, communicates with the upper part of the said
boiler or source of water supply. Water is thus caused to pass through or circulate
in ench of the pipes in the direction shewn by the arrows in the drawing.
The intermediate or junction pipes al a² at the points where they enter the said
receivers EE, are fitted with valves ele, which may be maintained in a raised
position by springs, the power of which is only sufficient to retain them in
that position so long as the operation of the whole arrangement is normal.
It will be understood therefore, that if any one of the pipes a should happen
to be burnt or broken, the high pressure of the water in the receivers will cause
the said valves, corresponding to the damaged pipe, to be closed instantly,
so that that pipe shall be isolated from the rest, while the circulation uninterruptedly
continues in all the other pipes.
Each of the connecting pipes a' a², may also be provided with a valve or cock
enabling the attendant completely to isolate the injured pair of pipes which will
soon melt and be finally destroyed by the intense heat prevailing in the furnace.
If the circulation pump or the like happens to discontinue its operation it is
important that there should be formed in the pipes a, a sufficient circulation of
water to prevent their being deteriorated until the pump resumes its normal
operation.
To attain this result there is fitted to the nozzle of the receiver E, at which
the water first arrives from the pump, a species of valve-chest G (Figure 2) which
receives a pipe lending from the circulation pump, while another pipe H connects
the said chest G with the lower part of the boiler direct. The orifices of these
two pipes are provided with valves g'g', connected for example by a jointed lever
so that when one of the valves is closed, the other is open, care being taken,
moreover, that the valve g of the pipe F is heavier than the valve of the
pipe H, or that the lever arm of the valve g' be longer than that of the valve g
or that the same end be attained by other means.
Hence it will be understood that whenever it should happen that the pump
stops operating the valve g, being the heavier one of the two, will immediately
descend upon its seat, while the other valve being raised, the boiler water will
freely be admitted through the pipe H, which it controls and be allowed to pass
through the circulation tubes owing to the water being by that time superheated,
in which case steam bubbles may form in the water, the density of the water being
diminished in consequence.
But the moment the pump starts working afresh, the water forced back by its
action, will raise the heavier of the two valves g', and close the other valve of
the pipe communicating with the lower part of the boiler, thereby restoring
the compulsory circulation of water through the apparatus.
The pivot of the lever comecting the two valves gg, may carry outside of the
valve case G, an index pin or style which imlicates the relative positions of the
said valves, and thereby enables the attendant to ascertain whether the pump
operates satisfactorily or not, so that he can if necessary, displace or readjust the
said valves g g by land,
I do not limit myself to the precise details described as any equivalent arrange-
ment may be employed for the attainment of the same purpose.
Fig. shews the arrangement of circulation pipes a when the gases issning from
the furnace are to circulate in lower and lateral ilues before entering the boiler tubes,

page_text: as provided for in the Specification of Letters Patent of the 1st December 1893,
No. 23,122. In this case the circulation pipes a are extended beyond the
furnace, within the combustion chamber D, and in that part, each pair of pipes
will be embedded in a casing i which may be of cast iron or steel, having the
shape of a key-stone, and forming, in conjunction with the others, the whole or
part of the arch necessary for guiding the hot gases in the desired direction.
The means described for carrying out this invention may of course he varied
for example, the circulation tubes or pipes may be provided with cast steel casings
or jackets throughout their lengths, so as to form a kind of longitudinal rib ensuring
sufficient rigidity to obviate the necessity for any intermediate supports for the
said tubes or pipes.
Having now particularly described and ascertained the nature of iny said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. In combination with steam boilers having internal furnaces, a series of tubes
or passages above the grate and arranged in pairs as described communicating at
their rear parts, the two free ends of a pair communicating each with a separate
receiver, these receivers being connected with the boiler or source of water supply,
and a pump or like device for causing an active circulation or passage of water
through the said tubes or passages substantially as and for the purposes herein-
before described.
2. In combination with steam boilers having internal furnaces a series of tubes
above the grate through which tubes water is caused to pass or circulate; each
tube being provided with a block or casting extending through a part or the
whole of its length and having the section of an arch or keystone, substantially as
hereinbefore described.
3. In combination with the water circulating tubes or passages above the grate
as above described and claimed a valve adapted for each tube or passage substan-
tially as and for the purpose hereinbefore described.
4. In combination with the circulating tubes or passages hereinbefore described
and claimed two separate receivers with which the ends of the pipes or passages
communicate, one of the said receivers being fed by a pump or the like with water
from the lower part of the boiler and the other receiver communicating with the
upper part of the said boiler substantially as hereinbefore described.
5. The combination with the water circulating tubes or passages and the
receiver fed by the pump as hereinbefore described and claimed of a valve chest
connected with the feed pipe from the pump or the like and a pipe connected
with the lower part of the boiler, the said two pipes being provided with valves
of unequal weight (or equivalently arranged) and connected together and arranged
so that they can be operated from the outside, substantially as and for the purposes
hereinbefore described.
6. In combination with the internal furnace of a steam boiler in which the
gases from the furnace circulate in lower and lateral flues before entering the
boiler tubes; the water circulating pipes or passages extending into the combus-
tion chamber in which each tube or passage is embedded in a casing having the
shape of a keystone forming, in conjunction with the others, the whole or part of
an arch substantially as and for the purposes, hareinbefore described with reference
to Fig. 4 of the accompanying drawings.
Dated this 23rd day of March 1895.
JOHNSONS & WILLCOX,
Agents.