Improvements in or connected with Steam Generators and their Furnaces:
Year: 1893

page_text: Date of Application, 1st Dec., 1893
Complete Specification Left, 28th Mar., 1894-Accepted, 9th June. 1894.
PROVISIONAL SPECIFICATION.
Improvements in or connected with Steam Generators and their
Furnaces:
I, JAMES YATE JOHNSON of 47 Lincoln's Inn Fields in the County of Middlesex,
Gentleman do hereby declare the nature of this invention (which has been com-
municated 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 multiple furnace steam generators
such as are employed more particularly in the Navy and enables a forced draught
to be employed under good conditions that is to say by completing the combustion
of the gases before they enter the boiler tubes and obviating the partial obstruction
of these tubes by cinders or sparks.
The invention is applicable to all descriptions of tubular boilers constructed with
more than one furnace or fire box and the improvements can be readily applied to
existing boilers.
The invention consists essentially in suppressing or dispensing with one of the
furnaces and causing the gases from the other furnace or furnaces to perform a
double circulation in the cylindrical chamber or flue corresponding with the furnace
that is dispensed with, before entering the tubes of the boiler.
The arrangement employed for boilers constructed with three furnaces or fire-
boxes for example consists in providing the two side furnaces only with fire bars
and causing the gases passing from these two furnaces to perform a double transit
in the intermediate or central flue which is divided with this object by a longitudinal
partition, before they enter the three series of boiler tubes leading to the smoke
box or funnel.
With this object the furnace or combustion chamber is so arranged as to enclose
the extremities of the three shells and of the three series of tubes and this chamber
is divided into two parts by means of a horizontal partition so arranged as to cause
the extremities of the fire places or furnaces to communicate with the part of the
intermediate body or shell situated below the aforesaid partition and place the
upper part of this shell in communication with the three series of boiler tubes.
The gases resulting from the combustion of the fuel in the furnaces after
passing over the bridges descend into the compartment of the combustion chamber
situated below the aforesaid dividing partition and pass into the lower part of the
intermediate body or section of the boiler which reconducts them to the front.
They then flow around the end of the horizontal partition placed in the said inter-
mediate body or section and return to the back of the boiler where they enter the
upper compartment of the smoke box and return through the tubes before escaping
into the chimney.
Under these conditions the cinders or sparks carried along with the current of
air are deposited in the intermediate section or chamber from which they can be
removed with facility either through the furnace door or through a cleaning opening
situated at the back. Moreover the combustion is effectually completed. in this
intermediate chamber by reason of the elevated temperature existing there and the
mixing of; the gases which pass through it.

page_text: Hollow vertical partitions which divide the upper part of the combustion chamber
are provided with bent extensions which regulate the flow or passage of the gases
at the time of their arrival in the boiler tubes.
The employment of a forced draught with this arrangement enables a much and
even more coal to be burned in the two furnaces as would be consumed in the three
furnaces working with a natural draught and consequently the generation of steam
can be husbanded or augmented as required.
When the improved system has to be applied to boilers in which the tubes are
placed in a line with the furnaces the means employed are the same as, bereinbefore
described.
In the case of a boiler with two furnaces one only is provided with fire bars and
the other is divided according to this invention by a longitudinal partition arranged
vertically being of any suitable construction being composed of firebrick or refractory
materials formed by a flat water chamber for example. In the cylindrical or other
combustion chamber there is also provided a vertical partition which compels the
gases from the fire place occupied by the fuel to enter the chamber or flue con-
taining the aforesaid longitudinal vertical partition around which they flow
subsequently returning to the compartment or chamber at the rear whence they
pass into the boiler tubes and from thence into the smoke box under the funnel.
or chimney. A partition or baffle plate is provided for the purpose of causing the
gases to be equally distributed in the boiler tubes or any other suitable device or
arrangement may be employed for this purpose.
This arrangement also provides for a complete combustion of the gases before
they enter the tubes and the ashes or cinders carried over can be easily removed
through the door or through the cleaning openings.
It will be readily understood from the examples hereinbefore described that the
invention can be applied without difficulty to all descriptions of tubular boilers
with multiple furnaces irrespective of their particular shape and arrangement.
Dated the 1st day of December 1893.
J. H JOHNSON & Co.,
47, Lincoln's Inn Fields, London, W.C., Agents.
COMPLETE SPECIFICATION.
Improvements in or connected with Steam Generators and their
Furnaces.
I JAMES YATE JOHNSON of 47 Lincoln's Inn Fields in the County of Middlesex
Gentleman, do hereby declare the nature of this invention (which has been com-
municated to me from abroad by Jean Pierre Serve of 17 Quai de Cuire Lyons
(Rhone) 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 multiple furnace steam generators
such as are employed more particularly in the Navy and enables a forced draught
to be employed under good conditions that is to say by completing the combustion
of the gases before they enter the boiler tubes and obviating the partial obstruction
of these tubes by cinders or sparks.
The invention is applicable to all descriptions of tubular boilers constructed with
more than one fire box or furnace and the improvements can be readily applied to
existing boilers.
The invention consists essentially in suppressing or dispensing with one of the
furnaces and causing the gases from the other furnace or furnaces to perform a
double circulation in the cylindrical shell or flue corresponding with the furnace
that is dispensed with, before entering the tubes of the boiler.
"

page_text: And in order that my said invention may be fully understood I shall now proceed.
more particularly to describe the same and for that purpose shall refer to the several
figures on the annexed sheet of drawings the same letters of reference indicating
corresponding parts in all the figures.
Figure 1 of the accompanying drawings represents in transverse section taken
on the line 1. 2 Figure 2 an ordinary marine boiler having three furnaces.
Figure 2 is a longitudinal vertical section taken through the centre line of the
boiler and Figure 3 is a transverse section of the same along the line 3. 4 of
Figure 2.
Figure 4 is a transverse vertical section (along the line 5. 6 of Figure 5) of a
boiler with two furnaces in which the tubes are placed in a line with the said
furnaces. Figure 5 is a horizontal longitudinal section of the same and Figure 6
is a transverse vertical section taken on the line 7. 8 (Figure 5) and Figure 7 is a
detail section of part of the apparatus shewn in Figures 1, 2 and 3.
The arrangement employed for boilers constructed with three furnaces or fire
boxes as shown for example in Figures 1, 2 and 3 consists in providing the two
side furnaces only A A2 with fire bars and causing the gases passing from these
two furnaces to perform a double transit in the intermediate or central shell or
flue A (which is divided for this object by a longitudinal partition D) before they
enter the three series of boiler tubes B B B2 leading to the smoke box or funnel C.
For this purpose the combustion chamber E is so arranged as to enclose the ends
of the three furnaces or shells A A' A' and the three series of boiler tubes B B' B2,
and this chamber is divided into two parts by means of a partition F so arranged
that the ends of the furnaces A. A² communicate with the part of the intermediate
or central flue or shell A situated below the horizontal partition D, the upper part
of the said flue A' being in communication with three series of boiler tubes B B¹ B²
as shewn in Figure 1.
The gases resulting from the combustion of fuel on the fire bars G in the
furnaces A A2 after passing over the bridges H, descend into the compartment of
the combustion chamber situated below the partition F and pass into the lower
part of the intermediate flue A' which reconducts them to the front of the boiler.
They then flow around the end of the horizontal partition D in the said intermediate
Alue A as indicated by the arrows and return to the back of the boiler where they
enter the upper compartment of the combustion chamber and return through the
series of tubes B B₁ 'B' before escaping into the chimney.
Under these conditions the ashes or cinders carried along by the current of air
are deposited in the intermediate chamber A' whence they may readily be removed
either through the door I, or through the cleaning opening J situated at the back
of the boiler. Moreover the intermediate chamber A serves to complete the
combustion of the gases by reason of the high temperature existing therein and the
mixing of the said gases which pass through it.
In order to insure complete combustion the partition D is preferably made in
the form of a hollow plate, furnished in its interior with baffles d as seen in
Figure 7 between which the air drawn in by the pipe a circulates before leaving by
the holes b made at the rear end of the underside of the said hollow plate. The
air which has thus become greatly increased in temperature meets the current of
gases, as shown by the small arrows, and assists in completing the combustion;
any excess of warm air drawn in does not materially affect the working since the
heat, which it contains is recovered or utilized by its passage through the series of
tubes B B B
Any other suitable arrangement in place of that described may be employed for
heating the air.
Hollow vertical partitions K which divide the upper part of the combustion
chamber E are provided with bent extensions as at K which regulate the flow
or passage of the gases at the time of their arrival in the series of boiler
tubes B B B².
The employment of a forced draught with this arrangement will enable as much

page_text: and even more fuel to be burned in the two furnaces A.Aas would be consumed in
the three furnaces working with a natural draught and consequently the generation.
of steam can be husbanded or augmented as required.
When the improved system has to be applied to boilers in which the series of
tubes are placed in a line with the furnaces the means employed are the same as
herein before described.
In the case of a boiler with two furnaces as shewn for example in Figures +, 5
and 6 one furnace (A) only is provided with fire bars G and the other A' is divided
by a longitudinal vertical partition D of any suitable construction being composed
for example, of fire brick or refractory materials or formed by a flat water chamber
communicating by tubes with the interior of the boiler.
In the cylindrical combustion chamber L a vertical partition M is provided
which compels the gases coming from the fire place G, containing the fuel to enter
the chamber or flue A containing the longitudinal vertical partition D around
which they flow as shewn by the arrows in Figure 5 subsequently returning to the
compartment or chamber L. at the rear of the partition M, whence they pass into
the boiler tubes B, and thence into the smoke box N and to the chimney. A
partition or baffle plate O is provided for the purpose of causing the gases to be
equally distributed amongst the boiler tubes, or any other suitable arrangement or
device may be employed for this purpose.
This arrangement, like that first described, provides for a complete combustion
of the gases before they enter the tubes, and the ashes or cinders carried over into
the intermediate chamber A¹ may be readily removed through the door I or the
cleaning openings P.
To secure the more economical working of these boilers there may be arranged,
preferably in the chimney C, or in the parts leading thereto a superheater such
as R, Figures 1 and 2, which may be employed for heating the feedwater, or the
air for promoting combustion in the furnaces or for drying or super-heating the steam
from the boiler.
The invention is not limited to the particular constructions and arrangements
shewn in the drawings, as it will be readily understood from the examples herein-
before described that the invention can be readily applied to all descriptions of
tubular boilers with more than one furnace irrespective of their particular shape
and arrangement. The partitions F and M arranged in the combustion chamber
may be of metal or of firebrick or other refractory material. In the case of a
boiler with three furnaces as in Figures 1, 2 and 3, the intermediate or central
flue A may be divided into three chambers by two vertical partitions, the side
chambers thereof corresponding to the parts A and A2, and the central chamber
serving to return the gases to the back of the boiler.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. In multiple furnace steam generators, the combination with one of the said
furnaces or flues, in which the grate or fire bars is or are dispensed with and
replaced by a partition or partitions of a combustion chamber, having partitions so
arranged that the gases coming from the furnace grates perform a double transit in
the flue provided with a partition or partitions and are then distributed in the boiler
tubes substantially as hereinbefore described.
2. In steam generators with three furnaces the combination of the furnaces A A
with grates or fire bars G, the intermediate or central flue A' with a longitudinal
partition or longitudinal partitions D, and the combustion chamber E, divided into
two chambers by the partition F, and having the depending partitions.K for
distributing the heated gases in. the tubes, substantially as hereinbefore described
and illustrated in Figures 1. 2 and 3 of the accompanying drawings.
3. In steam generators with two furnaces, the combination of the furnace A, with
grate or fire bars G, and the furnace or flue A' with a longitudinal partition D,

page_text: and the combustion chamber L, divided into two chambers by the partition M, and.
having baffle plates or partitions O, for distributing the heated gases in the tubes.
substantially as hereinbefore described and illustrated in the accompanying.
drawings.
Dated this 28th day of March 1894