IMPROVEMENTS IN THE GENERATION OF STEAM
Year: 1855

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields,
in the County of Middlesex; and of Glasgow, North Britain, Gentleman,
for the Invention of "IMPROVEMENTS IN THE GENERATION OF STEAM"-A
communication from Paulin Jean Charles Montety, of Toulon, in the
Empire of France.
Sealed the 27th March 1855, and dated the 29th January 1855.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at
the Office of the Commissioners' of Patents, with his Petition, on the
29th January 1855.
1. JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of
Middlesex, and of Glasgow. North Britain, Gentleman, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN THE GENERATION CF STEAM,"
a communication from Paulin Jean Charles Moniety, of Toulon, in the
Empire of France, to be as follows:-
This Invention relates to certain improved constructions and arrangements.
of steam boilers or generators for locomotive, marine, or stationary engines,
whereby a great economy both of fuel and water is obtained, as well as the
advantage of having a compact and inexpensive boiler.
The improvements consist, first, in the employment of a peculiar apparatus
for drying and surcharging or superheating the steam before using it; second,.
in the peculiar construction and arrangement of evaporating apparatus to be
used in connection. with steam boilers.
In the arrangement for marine boilers, the flame on leaving the furnaces
Price S1

page_text: enters a chamber situated over each set of fire bars, which chamber is filled
with a coil or coils of steam pipes, which I term, for distinction, surchargers,"
communicating at one end with the top of the boiler, and at the other extremity
with a transverse steam passage, situated inside the boiler, which passage is
enclosed in brickwork or fire clay. After traversing the first chamber, the
flame and heated air pass out by lateral openings into two chambers situated
on each side of the furnaces, such chambers being filled with a series of hori-
zontal pipes or tubes, which afford a passage for the flame and heated air. On
leaving these tubes, the heated air and smoke from each furnace ascend to two
chambers situated immediately over the first-mentioned chambers; these latter
chambers are also filled with a coil or coils of steam pipes, which I term "steam
dryers. Such coil or coils form a continuation of the pipes which constitute
the coils of the first chamber, and serve to dry the steam which enters them
from the top of the boiler before it proceeds to the lower coils or surchargers,
where it is subjected to the direct action of the flame, whilst in the upper coils
or dryers it is merely acted upon by the heated air and gases. The steam,
having descended from the top of the boiler down the whole length of the coils,
finally enters, in a highly surcharged state, the transverse passage herein-before
referred to, whence it passes to the cylinder, which may be also enclosed in
brickwork or fire clay to prevent any loss from radiation. Each coil is fitted
with two cocks or stop valves, so as to afford facility for shutting off the steam
from any individual coil in case of leakage. This construction of marine boiler
affords facility also for consuming, the smoke of the furnace, by admitting
currents of air at the sides under the coils and in the bridge. The gases,
moreover, are brought into direct contact with the coils, which are heated by
the steam and flame to an intense heat, thereby tending greatly to their
ignition. The evaporators which I propose adapting to steam boilers consists
of a great number of copper tubes of small diameter opening into chambers,
the whole being enclosed in an outside casing and surrounded with water. The
first of the chambers communicates with the feed pipe, and the last with the
boiler by two other pipes. This evaporator may either be used vertically or
horizontally, the same principle being carried out in each. In locomotive
engines the same principle of coiled pipes is carried out for drying and sur-
charging the steam, such coils being situated in a large central fluc in the
barrel of the boiler. The evaporator in this case is placed vertically near the
bottom of the chimney. The tubes of the evaporator absorb not only the waste
heat passing up the chimney, but also the heat given off by the steam from
the blast pipe. The evaporator may be replaced by a number of drying tubes
situated in the chimney. If, however, the draught should be deteriorated by

page_text: the use of the evaporator or steam drying pipes, a fan may be placed near the
top of the chimney and worked by the engine to assist the draught. By a
very slight modification, the system of drying and surcharging tubes may be
applied to ordinary stationary engine boilers. If the boiler is made with a
central flue. the pipes or coils are fitted in such flue immediately behind the
bridge the same arrangement being observed with regard to those with
external flues, the coils being in that case placed in the flue, but slightly
elevated from the bottom by a suitable series of supporting bars.
SPECIFICATION in pursuance of the conditions of the Letiers Paient, filed
by the said John Henry Johnson in the Great Seal Patent Office on the
. 28th July 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
and of Glasgow. North Britain, 'Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-ninth day of January, in the year of our
Lord One thousand eight hundred and fifty-five, in the eighteenth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto me.
the said John Henry Johnson, Her special license that I. the said John
Henry Johnson, my executors, administrators, and assigns, or such others
as I, the said John Henry Johnson, my executors, administrators. or assigns,
should at any time agree with, and no others, from time to time and at
all times thereafter during the term therein expressed, should and lawfully
might make, use, exercise, and vend, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an Invention
for "IMPROVEMENTS IN THE GENERATION OF STEAM," a communication from
Paulin Jean Charles Montety, of Toulon, in the Empire of France, upon the
condition (amongst others) that 1. the said John Henry Johnson, by an
instrument in writing under my hand and seal, should particularly describe
and ascertain the nature of the said Invention, and in what manner the
same was to be performed, and cause the same to be filed in the Great Seal
Patent Office within six calendar months next and immediately after the date
of the said Letters Patent.
NOW KNOW YE, that I, the said John Henry Johnson, do hereby declare
the nature of the said Invention, and in what manner the same is to be

page_text: performed, to be particularly described and ascertained in and by the fol-
lowing statement, reference being had to the accompanying Drawings, and to
the letters and figures marked thereon, that is to say:-
The said Invention relates to certain improved constructions and arrange-
ments of steam boilers or generators for locomotive, marine, or stationary
engines, whereby a great economy both of fuel and water is obtained, as well
as the advantage of having a compact and inexpensive boiler.
The improvements consist. first, in the employment of a peculiar apparatus
for drying and surcharging or superheating the steam before using it; second,
in the peculiar construction and arrangement of evaporating apparatus to be
used in connection with steam boilers.
In the arrangement for marine boilers, the flame on leaving the furnaces
enters a chamber situated over each set of fire bars, which chamber is filled
with a coil or coils of steam pipes, which I term, for distinction, surchargers or
dilators, communicating at one end with the top of the boiler, and at the other
extremity with a transverse steam passage, situated inside the boiler, which
passage is enclosed in brickwork or fire clay. After traversing the first
chamber, the flame and heated air pass out by lateral openings into two
chambers situated on cach side of the furnaces, such chambers being filled
with a series of horizontal pipes or tubes which afford a passage for the flame
and heated air. On leaving these tubes, the heated air and smoke from each
furnace ascend to two chambers situated immediately over the first-mentioned
chambers. These latter chambers are also filled with a coil or coils of steam
pipes, which I term steam dryers." Such coil or coils form a continuation of
the pipes which constitute the coils of the first chamber, and serve to dry the
steam which enters them from the top of the boiler before it proceeds to the
lower coils or surchargers, where it is subjected to the direct action of the flame,
whilst in the upper coils or dryers it is merely acted upon by the heated air
and gases. The steam having descended from the top of the boiler down the
whole length of the coils, finally enters, in a highly surcharged state, the trans-
verse passage herein-before referred to, whence it passes to the cylinder, which
may be also inclosed in brickwork or fire clay, to prevent any loss from radia-
tion. Each coil is fitted with two cocks or stop valves, so as to afford facility
for shutting off the steam from any individual coil in case of leakage. This
construction of marine boiler affords facility also for consuming the smoke of
the furnace, by admitting currents of air at the sides under the coils and in the
bridge. The gases, moreover, are brought into direct contact with the coils,
which are heated by the steam and flame to an intense heat, thereby tending
greatly to their ignition. The evaporator which I propose adapting to steam

page_text: boilers consists of a great number of copper tubes of small diameter opening
into suitable chambers, the whole being inclosed in an outside casing and
surrounded with water; the first of the chambers communicates with the
feed pipe, and the last with the boiler by two other pipes. This evaporator
may either be used vertically or horizontally, the same principle being carried
out in each. In locomotive engines, the same principal of coiled pipes is
carried out for drying and surcharging the steam, such coils being situated
in a large central flue in the barrel of the boiler; the evaporator in this case is
placed vertically near the bottom of the chimney. The tubes of the evaporator
absorb not only the waste heat passing up the chimney. but also the heat
given off by the steam from the blast pipe. The evaporator may be replaced
by a number of drying tubes situate in the chimney. If, however, the
draught should be deteriorated by the use of the evaporator or steam drying
pipes, a fan may be placed near the top of the chimney and worked by the
engine to assist the draught. By a very slight modification, the system of
drying and surcharging the steam may be applied to ordinary stationary engine
boilers. If the boiler is made with a central flue, the pipes or coils are fiited
in such flue immediately behind the bridge; the same arrangement being
observed with regard to those with external flues, the coils being in that
case placed in the flue, but slightly elevated from the bottom by a suitable series
of supporting bars.
It is necessary during the working of the engine that the steam of the
boiler and that of the evaporator should be in communication by means of an
upper pipe; also, that the feed pipe should force the water round the exterior
of the tubes of the evaporator to the level of the first tube of communication
between the evaporator and the boiler, the water thereby entering the boiler by
its own gravity. After having produced its mechanical effect in the cylinder,
the steam passes down the evaporator before being delivered into the atmosphere
or the condenser. By this system of working, the steam in its exit from
the cylinder, having a temperature far above that of the steam in the boiler,
converts the upper part of the water in the evaporator into steam.
When once reduced to the temperature of the steam in the boiler, it passes
down the evaporator and imparts a certain portion of its caloric to the
coldest water that it encounters round the tubes of the evaporator. The
water, therefore, does not arrive at the first tube of communication with the
boiler before it has been elevated to the temperature of the steam therein.
Consequently, by means of this apparatus, not only is a certain quantity of
heat gratuitously obtained, but the feed water arrives in the boiler at a tempé-
rature at which it will require no further expenditure of caloric to convert it

page_text: into steam. The necessary modifications in the construction of various kinds
of boilers in order to adapt them for the application of my apparatus will
be easily understood on referring to the accompanying Sheets of Drawings.
Fig. 1 on Sheet of the Drawings, represents an end elevation and
transverse section of a marine boiler, taken above the line 1, 2, in Fig. 3;
Fig. 2 represents a sectional plan of the same. taken at different heights:
and Fig. 3 is a longitudinal section of the boiler, taken along the line 3, 4,
in. Fig. 1.
The flame on passing from the furnace A enters a chamber surrounded
with water, and containing the serpentine tubes B. which may be termed the
dilators. as the object of this part of the apparatus is to dilate the steam.
On leaving this chamber, the flame is diverted through a lateral opening or
passage in order to traverse the group of horizontal tubes C. From these
tubes nothing more than smoke is emitted. which smoke is of the ordinary
temperature of smoke emitted from a tubular boiler. This smoke now
traverses the chamber containing the serpentine D, which I term the dryer,
as its object is to dry the steam. Thus a portion of the heat retained in the
smoke even is turned to good account.
Each tube of the drying serpentine is in communication with a tube of
the dilating serpentine. It is in the passage of the steam from one tube in
the other that the novelty of this Invention in reality commences, the watery
particles in the steam not being removed by traversing the drying serpentines
only, inasmuch as a first separation takes place above the chambers containing
the drying serpentines. The space comprised between these drying chambers
and the roof of the boiler is in communication only with the main steam
chamber at the end furthest from the chimney, and the entrance to the
serpentines is on the end nearest the chimney.
The steam is thus obliged to traverse the whole length of the boiler, and
as the section of the steam space in the boiler is considerably larger than that
of the serpentines combined, the movement of the steam will be excessively
slow; consequently the globules of water fall by virtue of their gravity on
to the roof of the drying chamber and are there vaporised, this roof being
heated by the smoke to a high temperature. After having traversed the
drying and dilating serpentines, the steam is delivered into the transverse
passage E, surrounded by brickwork. This passage is extended both right.
and left outside the boiler until it reaches the steam cylinders, which are also
surrounded by brickwork, sand, or other good non-conductor of heat. Each
separate tube of the serpentines is furnished with two cocks or valves, b and
d, whereby the communication between the boiler and any particular tube

page_text: may be intercepted. By this means, if the apparatus be not properly adjusted,
or if through accident or wear it requires renewing, it will be easy by
shutting these cocks or valves to prevent the entrance of steam therein,
whilst at the same time the working of the engine will not be interfered
with, and a new tube may be readily inserted, since the joints of such tubes
are placed outside the boiler. The steam, on passing through the serpentines
B, enters by the outside coil, and passes along the pipe until it reaches the
inner coil, which conducts it to the inner coil of the next pipe or serpentine,,
and after passing along the coils of that pipe it enters the passage E, as
will be clearly understood on referring to Figs. 1 and 3 on Sheet 1 of the
Drawings, the serpentines being thus coupled in pairs.
In marine boilers it has hitherto been found difficult to consume the smoke,
for two reasons; first, the difficulty of obtaining air, in consequence of the
volume of the boilers and the danger of fires on board ship; second, the fur-
nace being surrounded on all sides with comparatively cold surfaces, the
gases immediately lose their heat, and then have not the power of becoming
inflamed on coming in contact with the air. In this improved arrangement
of boiler, on the contrary, it will be found perfectly practicable to force
a lateral current of air under the inclined plane of the tubes and penetrating
the masonry of the bridge; 2nd, the gases, instead of becoming cooled
against the sides of the chambers, come in contact with the serpentine tubes,
which are at a temperature of about 900°, such temperature being amply
sufficient to inflame them in a current of cold air. It is an acknowledged
fact, that were it possible to prevent the formation of smoke in marine
boilers it would be a very great advantage to the naval service, and in time
of war vessels would not be discovered by the long trails of smoke which
follow them.
Fig. 4, on Sheet of the Drawings, represents a longitudinal vertical
section of the improved evaporator, taken through the line 3, 4, in Fig. 5; and
Fig. 5 is a transverse section and end. elevation of the same, taken along the
line 5, 6, in Fig. 4. This apparatus is composed, as will be seen, of a number
of small copper tubes t, t, opening into the chambers or compartments T, T¹, T²,
and T the whole are surrounded with water, and are enclosed in ટી.
or outside casing V of any convenient form. The first or lower compartment
chamber
T communicates with the feed pump, and the last or highest one T is in
communication with the boiler by means of two tubes or feed pipes.
Figs. 6 and 7 represent respectively a vertical and transverse section of
a vertical evaporator. The tubes f, which are bound together, rest at their
lower extremities on the top of the cast-iron chamber T and are fitted at their

page_text: upper ends into the chamber T', which is in communication with the boiler.
The pipe or inlet R is in communication with the feed pump, and that at
S with the boiler, which it supplies with water previously heated in its passage
through the evaporator by the steam in the tubes. This apparatus is furnished
at its lower end with a cast-iron box T, filled with wire gauze, the object of
which is to prevent any radiation of heat into the condenser. The horizontal
evaporator is also furnished with a similar contrivance.
Fig. 1, on Sheet 2 of the Drawings, represents a vertical section, taken
through the axis or centre line of the boiler, of a locomotive engine fitted with
the improved apparatus; and Fig. 2 is a transverse section of the same, taken
along the line 1, 2, in Fig. 1.
The drying and superheating or dilating apparatus is placed in the body
of the boiler, and the evaporator placed in the lower portion of the chimney, or
. in the upper prolonged part of the smoke box.
On referring to these Figures, the position of the serpentine tubes B and D
will be easily seen, their arrangement being somewhat similar to the arrange-
ment of those of the marine boiler herein-before described. The serpentines
are placed in a cylindrical flue or tube E. The coils B start from the steam
chamber H, connected with the regulator 1; they approach the furnace or
fire box A in a spiral direction, and finally terminate in the compartment F,
which is separated from the chamber H by a division plate, both chambers
being enclosed in the smoke box G; from the compartment F the steam is
conducted to the cylinders by suitable steam pipes.
The tubes of the evaporator are placed in a vertical position, and take up
not only the caloric which remains in the smoke after its passage through the
coiled tubes B and D, but also the caloric from the exhaust steam of the
cylinder.
The evaporator may be replaced by drying tubes fitted into the chimney;
in either case should the draught be obstructed, a small fan might be placed
at the top of the chimney, which would be driven by the engine itself.
Fig. 3, on Sheet 2 of the Drawings, represents a longitudinal vertical section
of a stationary engine boiler, taken along the line 1, 2, 3, 4, 5, 6, in Fig. 5,
with the improved steam heating apparatus; Fig. 4 is a plan and partial hori-
zontal section of the same, the section being taken along the lines 7, 8, 9, 10,
in Fig. 3; and Fig. 5 is an end elevation and transverse section of the same,
the sectional part being taken along the line 11, 12, 13, 14, in Fig. 3.
In these Figures it will be seen that the same principles carried out
in the construction of the apparatus as in the preceding examples, the
arrangement only being so altered as to place the steam pipe D in com-

page_text: munication with either one or other of the boilers A and B. a cock C¹ being
placed between the two. A second cock F' serves to fill the whole apparatus
with water during the time of lighting the fire, so that the-apparatus may not
be burnt by being subjected to the hction of the flame when in
Fig. 6 represents the application of this system of superheating stea...
boiler with internal furnace, such as is frequently made at the present day.
state.
a
It is well known that the different kinds of boilers in use are very numerous,
and it would be obviously impossible to shew the application of this system
to all of them, but from what has already been shewn it will be evident what
modifications are necessary in its application to boilers of various constructions.
Having now described and particularly ascertained the nature of the said
Invention, and the manner in which the same is or may be used or carried into
effect, I would observe, in conclusion, that I do not confine or restrict myself to
the precise details or arrangements which I have had occasion to describe or
refer to as many variations may be made therefrom without deviating from
the principles or main features of the said Invention; but what I consider to
be novel and original, and therefore claim as the Invention secured to me by
the herein-before in pari recited Letters Patent, is,--
First, the general construction and arrangement of apparatus for drying and
dilating or superheating steam, as herein-before described.
Second, the system or mode of superheating or dilating the steam before it
enters the cylinders, by first drying it in a coil or coils of drying pipes and
subsequently superheating or dilating it in a coil or coils of pipes placed in
immediate contact with the flames issuing from the furnace.
Third, the peculiar constructions and arrangements of evaporators or feed
heating apparatus, as herein-before described.
In witness whereof, I, the said John Henry Johnson, have hereunto
set my hand and seal, the Twenty-eighth day of July, One thousand
cight hundred and fifty-five.
J. HENRY JOHNSON. (L.S.)