Improvements in connection with Boilers for the Production of Superheated Steam.
Year: 1895

page_text: PROVISIONAL, SPECIFICATION.
Improvements in connection with Boilers for the Production of
Superheated Steam.
I JAMES YATE JOHNSON of 47 Lincoln's Inn Fields, in the County of London,
Gentleman, do hereby declare the nature of this invention (a communication to
me from abroad by the Firm of Carl Pieper of No. 3 Hindersinstrasse
Berlin N.W. 40 in the Empire of Germany, Engineers) to be as follows :-
This invention relates to improvements in connection with steam boilers in which
water is converted into steam by the direct action of the fire, the steam thus
generated being then superheated, and the said invention consists in the adoption
of a new and improved method for the guidance or circulation of the combustion
gases, through or in connection with such steam boilers, whereby the useful effect,
obtained from the heat of such gases, becomes very considerable in comparison
with the small extent of the heating surfaces, in the construction of which a
material saving of cost may be accordingly realized. This reduction or contraction
of the area of the heating surfaces especially in the portion of the boiler where
the superheating of the steam is intended to take place is facilitated by conducting
the combustion gases not as is usual on the counter-current principle, but in a
current following the same direction as the steam to be superheated; so that the
whole of the existing difference of temperature, between the products of
combustion and the saturated steam flowing towards the superbeater, is utilised in
the process of transmission of the surplus heat of the combustion gases to the
steam. This arrangement of the superheater guiding the current of gases in the
same direction as the steam is not only rational regarded from the point of view of
the reduction of the superheating surfaces, it may also be so from that of the
economical use of heat, if the products of combustion to be sent to the superheater
have acted only on the most effective part of the boiler where the steam is
generated, so that the heat which the combustion gases still retain, as they leave
the superheater, may then be extracted from them and turned to account by
causing them in the subsequent stage of operation, to meet a part of the heating
surface in contact with water, which they had not touched before and which is
generally set apart for raising the temperature of the water, so that eventually
their temperature is reduced to a low degree at which they are fit to be discharged
through the chimney.
The described course of the furnace gases may be performed in a Cornish boiler
by firstly using the said gases in the flue for generating steam, then guiding thein
through the superheating chamber from the front to the rear, that is to say in the
same direction in which the steam traverses the superheating coil, and finally
bringing them into contact with the lower and coldest part of the boiler after
which they pass through the flue and thence escape through the chimney.
In the combination of a cylindrical boiler wherein the steam is generated,
having its fire arranged below, with another similar though smaller boiler which
serves for the preliminary heating of the water, the furnace gases or products of
combustion may heat both these boilers in succession and on their way from the
greater to the smaller one pass through the superheating chamber.

page_text: In another form of internal flue boiler adapted to be fed continously through a
preheating coil, the gases may be guided to heat in succession the flue, the steam
superheating coil and the water preheating coil.
Dated this 1st dor of July 1895
JOHNSONS & WILLCOX,
47 Lincoln's Inn Fields, London, W.C., Agents.
Improvements in connection with Boilers for the Production of
Superheated Steam.
I, JAMES YATE JOHNSON, of 47 Lincoln's Inn Fields, in the County of London,
Gentleman do hereby declare the nature of this invention, (a communication to
me from abroad by the Firm of Carl Pieper of No. 3, Hindersinstrasse
Berlin N.W. 40, in the Empire of Germany,) 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 connection with steam boilers in which
water is converted into steam by the direct action of the fire, the steam thus
generated being then superheated, and the said invention consists in the adoption
of a new and improved method for the guidance or circulation of the combustion
gases, through or in connection with such steam boilers, whereby the useful effect,
obtained from the heat of such gases, becomes very considerable in comparison
with the small extent of the heating surfaces, in the construction of which a
material saving of cost may be accordingly realized. This reduction or contraction
of the area of the heating surfaces especially in the portion of the boiler where
the superheating of the steam is intended to take place is facilitated by conducting
the combustion gases, not, as is usual, on the counter-current principle, but in a
current following the same direction as the steam to be superheated; so that the
whole of the existing difference of temperature, between the products of combustion
and the saturated steam flowing towards the superheater, is utilized in the process
This
of transmission of the surplus heat of the combustion gases to the steam.
arrangement of the superheater guiding the current of gases in the same direction
as the steam is not only rational regarded from the point of view of the reduction
of the superheating surfaces, it may also be so from that of the economical use of
heat, if the products of combustion to be sent to the superheater have acted only
on the most effective part of the boiler where the steam is generated, so that the
beat which the combustion gases still retain, as they leave the superheater, may
then be extracted from them and turned to account by causing them in the
subsequent stage of operation, to meet a part of the heating surface in contact
with water, which they had not touched before and which is generally set apart
for raising the temperature of the water, so that eventually their temperature is
reduced to a low degree at which they are fit to be discharged through the
chimney.
The described course of the furnace gases may be performed in a Cornish boiler
by firstly using the said gases in the flue for generating steam, then guiding them
through the superheating chamber from the front to the rear, that is to say in the
same direction in which the steam traverses the superheating coil, and finally
bringing them into contact with the lower and coldest part of the boiler after
which they pass through the box and thence escape through the chimney.
In a combination of a cylindrical boiler wherein the steam is generated, having
its fire arranged below, with another similar though smaller boiler which serves for

page_text: the preliminary heating of the water, the furnace gases or products of combustion
may heat both these boilers in succession and on their way from the greater to the
smaller one pass through the superheating chamber.
In another form of internal flue boiler adapted to be fed continuously through a
preheating coil, the gases may be guided to heat in succession the flue, the steam
superheating coil and the water preheating coil.
In the accompanying drawings three forms of superheating steam boilers
constructed according to this invention are shewn by way of example, in all of
which the furnace gases are made to follow the course already described.
Figure 1 of these drawings is a longitudinal section of a Cornish boiler,
embodying the subject of this invention, whereas Figure 2 illustrates, by way of
another example, in longitudinal section the invention applied to a boiler composed
of a larger cylindrical part and a smaller part, arranged underneath the same.
Figure 3 is a longitudinal section of another form of internal flue boiler, embodying
the subject of the invention.
In the arrangement of parts shown in Figure 1, the gases of combustion,
generated on the grate a, after having been used in the flue A for producing steam
and after having passed through the superheating chamber B, from the front to
the rear in the direction indicated by arrows, that is to say, in the same direction
in which the steam traverses the superheating coil, come into contact with the
lower and relatively coldest part C of the boiler. From here they pass through
the flue D and thence escape through the chimney. bis the pipe and valve
connection by means of which the superheating coil in the chamber B is fed with
the steam to be heated and a pipe conducts the superheated steam to the place
of cousumption.
In cases where a cylindrical boiler A is used for the generation of steam and in
combination therewith another similar but smaller boiler C is employed for the
preliminary heating of the feed-water, as indicated in Figure 2, the gases developed
on the grate a may heat both boilers in succession and on their way from the flues
of the greater to those or that of the smaller one they pass through the superheating
chamber B, in the direction shown by the arrows, and finally escape through flue D
in the chimney. The lower part C of the boiler being the coldest part of the
whole heating surface, a very considerable useful effect of the heat produced by
the combustible burnt on the grate is so secured.
The modification, represented in Figure 3, of the Cornish boiler shown in
Figure 1 also has the superheating chamber B arranged so as to be traversed
directly by the combustion gases escaping from the internal flue A, but, instead of
conducting the said gases back to the outer vessel of the boiler they are caused to
pass into a separate chamber C placed in proximity to the superheating chamber,
there to heat the water preheating coil. The water therein is fed by the pipe c
and enters, when preheated, the boiler by means of a feeding pipe c¹. The steam
to be superheated, as in the other examples, flows through pipe and valve
connection to the superheating coil iu B in the same direction as the combustion
gases and pipe b' leads the superheated steam to the place of its consumption.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
1. A boiler for the production of superheated steam, in which the combustion or
furnace gases are caused to take such a course, that they firstly act upon the most
effective part of the boiler where the steam is generated, then pass through a
superheater chamber, taking the same direction as the steam, and are, finally,
cooled down by coming in contact with the remaining or coolest portion of the
heating surface in contact with the water, all substantially as shown and described
with reference to the accompanying drawings.
2. The several forms of boilers for producing superheated steam, substantially

page_text: as hereinbefore described and illustrated in Figure 1, Figure 2 and Figure 3 of the
accompanying drawings.
Dated this 25th day of March 1896.
JOHNSONS & WILLCOX,
47 Lincoln's Inn Fields, London, W.C., Agents.