IMPROVEMENTS IN AND CONNECTED WITH APPARATUS FOR SUPERHEATING STEAM, PARTS OF WHICH IMPROVEMENTS ARE ALSO APPLICABLE TO OTHER SIMILAR PURPOSES
Year: 1877

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields, in the
County of Middlesex, Gentleman, for the Invention of "IMPROVEMENTS IN
AND CONNECTED WITH APPARATUS FOR SUPERHEATING STEAM, PARTS OF WHICH
IMPROVEMENTS ARE ALSO APPLICABLE TO OTHER SIMILAR PURPOSES." A com-
munication from abroad by Henri Prosper Olivier Lissagaray, of Paris, in the
Republic of France.
.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at the
Office of the Commissioners of Patents on the 11th December 1877.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN AND CONNECTED WITH APPARATUS FOR SUPERHEATING
STEAM, PARTS OF WHICH IMPROVEMENTS ARE ALSO APPLICABLE TO OTHER SIMILAR
PURPOSES." A communication from abroad by Henri Prosper Olivier Lissagaray,
of Paris, in the Republic of France.
This Invention relates to improved apparatus for superheating steam possessing
the following characteristics :-
1st. It admits of the weight being ascertained of the saturated steam introduced
into it per second at a given temperature.
2nd. It enables the superheated temperature to which the said steam is raised to
be accurately ascertained. This latter object is effected by mixing a known weight
of saturated steam at a given temperature with a known weight of superheated
steam, and computing by calculation from the readings of a mercurial thermometer
the temperature of the superheated steam.
3rd. It admits of the temperature of a chamber in which the superheating is
effected, being determined with precision by determining the constant weight per
second of heavy oil or other hydrocarbon liquid injected, vaporised, and combined
in the presence of a known weight of superheated air and steam introduced as the
medium of injection and vaporisation, and by determining the temperature to which
a known weight of vaporised water superheated by the gas of combustion is
raised.
4th. The apparatus is applicable to various industrial purposes,

page_text: In carrying out this Invention it is proposed to employ, in combination with a
superheater, a steam distribution valve, which may also be used separately as an
instrument for measuring the delivery of gases and vapours in general.
This improved valve or apparatus consists of a chamber connected on one side
with the supply pipe, and provided on the other side with a plate perforated with
holes, each of which holes communicates with an ordinary plug cock. These cocks are
connected at their other ends to a plate resembling the first, but provided with holes
of different diameters communicating with a chamber connected to the pipe through
which the fluid flows from the valve
A plate with finer perforations may be placed in the first chamber for the
purpose of intercepting any substances which might affect the working of the
apparatus This chamber may also be provided with an orifice for blowing off
the water of condensation, and the perforated plates connected to the cocks may
both be made with perforations of a uniform size, the difference in the sectional
area of the passages being obtained by the employment of nozzles or nipples with
holes of the required diameter inserted in the ends of the bodies of the cocks.
The flow of the fluid through this apparatus is regulated by opening one or more
of the plug cocks above referred to, and allowing the fluid to pass through one or
more of the larger or smaller holes, or all of them, as required. The sectional area
of the passage may thus be changed while preserving its circular form, the
respective cocks being always either closed entirely, or opened to their fullest
extent.
By means of this apparatus the sectional area of the passage may be varied
whilst the circular form is preserved.
In applying the apparatus for indicating elevated temperatures of superheated
steam and of gases and vapours in general, two sets of distributing valves, similar
to that herein-before described, are employed; the first delivers a known weight of
saturated steam at a given temperature to a special superheating apparatus, herein-
after described. After being superheated this steam meets a known weight of
saturated steam delivered by the second distributing valve. The temperature of
these two steams when mixed is indicated by a mercurial thermometer, whence the
temperature of the superheated steam may be ascertained. A fraction of the weight
of the superheated steam is employed in vapourising the oil or hydrocarbon of any
description used as fuel, and the weight of this fraction is also ascertained. By this
process therefore the temperature above that of boiling mercury is ascertained by
means of a mercurial thermometer.
Another part of this Invention consists in the use of a peculiar heating or super-
heating chamber for producing a constant temperature, with means of ascertaining
the same in a continuous manner. This apparatus consists of, say, three vertical
concentric cylinders with two annular spaces formed between them; the outer of
these two annular spaces is filled with sand for the purpose of preventing the
radiation of heat, and the inner one contains the steam to be superheated, and
which is introduced through a pipe at its upper part, and escapes through another
pipe near the bottom. The annular spaces are closed by double flanges provided on
the extremities of the middle cylinder, that is to say, the one situate between the
inner and outer cylinders, and which is also provided at intervals throughout its
length with internal flanges or projections forming annular perforated diaphragms,
through which the steam is compelled to pass. The flange at the lower extremity
of this cylinder also serves to support the bottom, which is provided with a corre-
sponding flange, and secured by bolts and nuts in the usual way with a packing of
asbestos. The bottom is of cylindrical shape, forming a continuation of the inner
cylinder, herein-before referred to, and is closed at its lower extremity by a plate
formed in one with it, and provided with a number of long tapering brass pius
projecting some distance into the cylinder; it is also formed with a hole in its
centre, connected to a pipe having two branches, one of which is for the supply of
heavy oil, and the other for superheated steam, the latter passes through a con-

page_text: tracted part formed in the pipe before it arrives at the oil, so as to meet the said
oil in the form of a jet, and thus inject it into the cylinder.
The water of condensation may be blown off through a suitable cock situate below
the contracted part. This jet of steam and oil is distributed in the cylinder by means
of a baffle plate arranged opposite the hole in the bottom, and dispersed among the
brass pins herein-before referred to, which assist in vaporising the oil. The air
required for combustion is supplied through a pipe or tuyere carried down the
centre of the inner cylinder to within a short distance of the extremities of the
brass pins in the bottom. This air pipe is also provided wth numerous perforations
in its cylindrical part near its lower extemity, which is closed by a thick circular
disc also provided with holes, which are formed so as to direct the air at a suitable
angle. This air, which has become superheated in passing through the pipe, meets
the mixture of vaporised oil and steam near the points of the brass pins, herein-
before referred to, where combustion takes place, the products of which pass up the
inner cylinder, superheating the steam in the annular space surrounding it, and
escape at the top.
In order to obtain a constant and uniform full supply, it is necessary that the
combustion chamber of the apparatus should be a source of uniform heat; this is
effected by regulating the amount of the various elements of combustion with
precision; moreover, this adjustment is checked by means of apparatus indicating
the temperature at all times
The various apparatus and their accessories are operated in the following manner -
The steam obtained from a suitable steam generator is conducted to the annular
space in the superheater, its passage being regulated by a valve of special con-
struction, as herein-before described.
The air for the support of combustion is obtained from a fan blower, which forces
it into a gasometer, whence it passes at a uniform pressure through a pipe provided
with a regulating valve of the construction herein-before described, to the com-
bustion chamber in the superheater.
The supply of oil for combustion in the superheater is obtained from a reservoir
heated by a worm connected to the steam pipe, herein-before referred to. This
reservoir is provided with a level regulator, the overflow from which is collected
and measured in a suitable receiver. The oil flows from the reservoir through the
level regulator, and along a pipe through a regulating valve of the peculiar con-
struction, herein-before described, to the bottom of the superheater, where it meets
a jet of superheated steam, and is consumed in the manner specified in the description
of the superheater.
The steam for injecting the oil is conducted through a pipe supplied either from
the superheater itself by a pipe and valve, or supplied direct from the boiler through
a pipe leading from the regulating valve, constructed according to this Invention,
connected to the steam pipe herein-before referred to.
The gases resulting from the combustion in the superheater escape at the upper
part of the same, as herein-before described, where they are collected in a suitable
pipe provided with a sliding or other valve to be distributed or employed, according
to the requirements of the user.
The temperature of the combustion may be ascertained by causing the gases
escaping from the superheater to pass through a cast-iron box supplied with water
from a reservoir provided with a level regulator, the overflow from which is collected
and measured in a suitable receiver, as described with reference to the reservoir
containing oil.
The elements of combustion employed consists of the weight of hydrocarbon
liquid, and the weight of air introduced per second.
In order to obtain the perfect uniformity of these weights, the liquid fuel is intro-
duced through an apparatus which is composed of,-
1st A level regulator provided with an overflow.
2nd. A graduated valve.

page_text: 3rd. Of a primary blower delivering a known weight of saturated steam per
second at a known temperature, and acting by a uniform propulsion; and of
a second blower delivering a known weight of superheated steam per second
at a known temperature acting in a uniform manner by heating and injection.
The level regulator may be placed in communication either with the reservoir of
hydrocarbon liquid, or with a graduated tube of a given section. When the
apparatus is working the oil passes directly from the reservoir to the level regulator;
but when it is desired to measure the delivery of oil per second, the communication
between the valve and the reservoir must be closed, and that between the graduated
tube filled with oil opened. The level regulator is then supplied by the volume
delivered by this tube during a given time, and as the flow of the liquid is kept up
by the overflow, the volume of liquid delivered by the valve is equal to the volume
delivered by the tube, minus the volume overflowing from the level regulator,
which is collected in a graduated guage glass.
This apparatus for measuring the delivery of an orifice under a uniform pressure
constitutes an important feature of this Invention.
The proportion between the weight of the oil and of hot air brought together
por second in the combustion chamber may be varied at pleasure, so that either
the complete combustion of the oil may be effected with a calculated excess of air, or
its incomplete combustion in known proportions and conditions for the purpose of
imparting either oxidising or reducing properties to the gases resulting from such
combustion.
In order to establish empirically the temperature of the combustion, a given
weight of water per second is poured into a cast-iron box situate in the passage of theso
gases, and its flow is rendered uniform by a level regulator similar to that employed
for the oil, the supply being so regulated that the steam obtained from it is super-
heated to a given temperature lower than that of boiling mercury. This temperature
is indicated by a thermometer placed in a tube forming a prolongation of the cast-
iron box.
It is evident that the caloric absorbed in evaporating and superheating the
weight of water is taken from caloric generated by the combustion (the weight of
the gases resulting therefrom may be calculated as the weight of oil, air, and steam
brought together per second is known.
The mean specific heat may also be ascertained by calculation).

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Henry Johnson in the Great Seal Patent Office on the 11th
June 1878.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman, "IMPROVEMENTS IN AND CONNECTED WITH APPARATUS FOR SUPER-
HEATING STEAM, PARTS OF WHICH IMPROVEMENTS ARE ALSO APPLICABLE TO OTHER
SIMILAR PURPOSES." A communication from abroad by Henri Prosper Olivier
Lissagaray, of Paris, in the Republic of France.
The said Invention relates to improved apparatus for superheating steam,
possessing the following characteristics :-
First. It admits of the weight being ascertained of the saturated steam intro-
duced into it per second at a given temperature T.
Second. It enables the temperature of superheating to which the said steam
is raised to be accurately ascertained. The measure of the value of may bo
ascertained by reducing the superheated steam to a temperature admitting of
being indicated by a mercurial thermometer. This cooling is effected by mixing
a known weight of saturated steam at the temperature T with a known weight of
superheated steam, the value of may then be completed by calculation.
Third. It admits of the temperature of a chamber in which the superheating
is effected being ascertained with precision by determining the constant weight per
second of heavy oil or other hydrocarbon liquid injected, vaporized, and combined
in the presence of a known weight of superheated air and steam introduced as the
medium of injection and vaporization, and by determining a certain temperature T,
being the temperature to which a known weight of vaporised water superheated by
the gas of combustion is raised.
The apparatus is applicable to various industrial purposes.
And in order that the 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 Sheets of Drawings, the same letters of reference
indicating corresponding parts in all the Figures.
Figures 1 and 2, Sheet 1, represent respectively a side elevation and plan of the
general arrangement and combination of apparatus employed in carrying out the
said Invention.
Figure 3, Sheet 2, is a sectional elevation, drawn to a larger scale, of heating or
superheating apparatus constructed according to the said Invention, the section
being taken along the line 1, 2, (Figure 5); Figure 4 is an elevation of the same;
and Figure 5 is a corresponding horizontal section taken along the line 3, 4,
Figure 3.
Figure 6 is a longitudinal section, and Figure 7 is a corresponding transverse
section, of a cock or valve of improved construction for regulating the supply of
dry steam.
Figure 8 is a longitudinal section, and Figure 9 is a corresponding transverse
section of a cock or valve of improved construction for regulating the supply of
compressed air.
The steam obtained from a suitable steam generator A, Figures 1 and 2, Shoot 1,
is conducted to an annular space in a superheater B, herein-after described, through
a pipe a, its passage being regulated by a valve 6 of the improved construction
herein-before referred to and shewn in detail in Figures 6 and 7 The air for the
support of combustion is obtained from a fan or blower C, which forces it into a
gasometer C, whence it passes to a combustion chamber in the superheater B at a
uniform pressure through a pipe c provided with a regulating valve i¹ of improved
construction, herein-before referred to, and shewn in detail in Figures 8 and 9.
The supply of oil for combustion in the superheater is obtained from a
reservoir D heated by a worm a' connected to the steam pipe a. This reservoir is
provided with a level regulator d (more fully herein-after described), the overflow
from which is collected and measured in a suitable receiver E. The oil flows from

page_text: the reservoir D through the level regulator d, and along a pipe through a
regulating valve E' of the description shewn in detail in Figures 6 and 7 to the
bottom of the superheater B, where it meets a jet of superheated steam, and is
consumed in the manner more fully herein-after explained.
The steam for injecting the oil is conducted by a pipe e, supplied both from the
superheater through pipes f. f, and valves f¹, f¹, and direct from the boiler through
pipes g, g, g, leading from a regulating valve G, the latter being connected to the
steam pipe a, and similar in construction to the valve b (Figures 6 and 7).
The gases resulting from the combustion in the superheater escape at the upper
part of the same, where they are collected in a suitable pipe H provided with a
sliding valve h, to be distributed or employed according to the requirements of the
user. In the arrangement illustrated in the Drawing they are conducted through
branch pipes Z and employed for heating a vessel X.
The temperature of the combustion may be ascertained by causing the gases to
pass through a cast iron box H' supplied with water from a reservoir I provided
with a level regulator I', the overflow from which is collected and measured in a
suitable receiver J, as more fully herein-after explained with reference to the
reservoir containing oil.
The superheater B, shown in detail in Figures 3, 4, and 5, Sheet 2, is constructed
with a view to producing a constant temperature with means of ascertaining the
same in a continuous manner, and consists of three vertical concentric cylinders,
marked respectively K, L, and M, with two annular spaces and formed between
then, the outer, k, of these two annular spaces being filled with sand for the
purpose of preventing the radiation of heat, whilst the inner one, l, contains the
saturated steam to be superheated, which is introduced through a pipe N at its
upper part, and escapes through a pipe N¹ near the bottom. The annular spaces
are closed by double flanges L provided on the extremities of the middle cylinder,
which is also provided at intervals throughout its length with internal flanges or
projections forming annular perforated diaphragms, through which the steam is
compelled to pass. The flange at the lower extremity of this cylinder also serves
to support the bottom O, which is provided with a corresponding flange and secured
by bolts and nuts in the usual manner, with an intervening packing of asbestos.
The bottom O is of cylindrical shape, forming a continuation of the inner
cylinder M, and is closed at its lower extremity by a plate formed in one with it
and provided with a number of long tapering brass pins o projecting into the
cylinder; it is also formed with a hole in its centre connected to a pipe P having
two branches p', p³, one of which, p', for the supply of heavy oil, communicates
with the valve E, Figures 1 and 2, Sheet 1, whilst the other, på, is for the supply
of superheated steam, the latter passes through a contracted part, p³, formed in the
pipe P before it arrives at the oil, so as to meet the said oil in the form of a jet, and
thus inject it into the cylinder.
The water of condensation may be blown off through a suitable cock Q situate
below the branch pipe 2². This jet of steam and oil is distributed in the cylinder
by means of a baffle plate o¹ arranged opposite the pipe P and dispersed among
the brass pins o, which assist in vaporizing the oil. The air required for combustion
is supplied through a pipe or tuyere c carried down the centre of the inner
cylinder to within a short distance of the extremeties of the brass pins o in the
bottom. This air pipe is provided with numerous perforations c³ in its cylindrical
part near its lower extremity, which is closed by a thick circular disc i provided
with holes c³, which are formed so as to direct the air at a suitable angle. This
air, which has become heated in passing through the pipe C, meets the mixture of
vaporized oil and steam near the points of the brass pins o, where combustion takes
place, the products of which pass up the cylinder M, superheating the steam in the
annular space l, and escape at the top through the pipe H, Figures 1 and 2.
The apparatus for regulating the supply of compressed air, illustrated in Figures
6 and 7, and that for regulating the supply of steam, illustrated in Figures 8 and 9,
are of generally similar construction, and may be employed to regulate the flow of

page_text: fluids for various purposes. These apparatus are constructed with a chamber R,
connected on one side with the supply pipe and provided on the other side with a
plate R¹, perforated with holes, each of which holes communicates with an ordinary
plug cock R. These cocks are connected at their other ends to a plate S¹
resembling the first, but provided with holes of different or varying diameters
communicating with a chamber S, connected to the pipe, through which the fluid
flows from the valve.
A plater (Figure 8) with finer perforations may be placed in the first chamber R
for the purpose of intercepting any substances which might affect the working of
the apparatus This chamber may also be provided with an orifice T (Figure 8)
for blowing off the water of condensation, and the perforated plates connected to
the cocks may both be made with perforations of a uniform size, the difference in
the sectional area of the passages being obtained by the employment of nozzles or
nipples U (Figure 8) with holes of the required diameter inserted in the ends of the
bodies of the cocks, and extending partly into the holes in the plates.
The flow of the fluid through this apparatus is regulated by opening one or more,
or the whole of the plug cocks R¹¹ as required, and allowing the fluid to pass
through one or more of the larger or smaller holes, or the whole of them, as the case
may be. The sectional area of the passage may thus be changed while preserving
the circular form, the respective cocks being always either closed entirely or opened
to their fullest extent.
Having thus described generally the construction of the apparatus, I shall now
proceed to explain the manner in which, with its use, the solution of the several
problems herein-before referred to may be effected.
The flow of saturated steam at the temperature T may be estimated or calculated
in the following manner :-
Let S be the sectional area of an orifice for the passage of steam.
The manometric tension being represented by H, the speed of the steam delivered
per second V = √196176 PH.
K being a co-efficient of contraction applied to the sectional area S in order to
ascertain the amount delivered let this co-efficient be equal to 0 5.
The amount of the delivery Q-S K ✓196176 H d.
In order to change the delivery Q the factors S or H may be varied. In practice
it is preferable to make H constant, and let S be variable.
For this purpose a common cock or valve would be wholly inapplicable, as by its
use not only would the variations of S be much too sudden, but also these varia-
tions in form accompanying the variations in sectional area might affect K. A valve
of the construction shown in detail in Figures 8 and 9, and herein-before described,
is therefore employed, as by its use the sectional area of the passage to be varied
whilst the circular form is preserved. The total sectional area of the passage is
composed of one or more circular orifices completely open; these orifices of various
diameters are in the example illustrated six in number, and of the following
diameters and areas (the metrical scale being adopted) videlicet―
The various combinations of these orifices, which are merely given by way of
example, and which may be modified as required with regard to their shape and
number for any other purpose (as herein-after stated with reference to the air-
blowing apparatus) are 62 in number, and the total section is 000001398.
In applying the apparatus for indicating elevated temperatures of super-heated
steam and of gases and vapors in general two sets of distributing valves similar to
that herein-before described are employed, the first (b, in the example illustrated)

page_text: delivers a known weight of saturated steam at a temperature =T' through an
orifice of a sectional area =S, which is conducted to the super-heating apparatus B
herein-before described. After being super-heated this steam is conducted through
pipes ffinto a pipe e, where it meets a known weight of saturated steam delivered
by the second distributing valve G, through an orifice of a sectional area = S. The
temperature of these two steams when mixed is equal to ☺, or nearly 250°, which
after passing through the combustion chamber in B is indicated by a mercurial
thermometer at w. The value of the temperature of the superhoated steam is
given by the formula,
© = §¹³ (0₁ = T + 0₁);
-
It is important to remark that the value of the co-efficient K of contraction does
not cause any error in this formula, it being a common factor.
It will be perceived moreover that whatever the value of may be it admits of
being reduced to another value ₁, capable of being ascertained by a mercurial ther-
mometer, because by increasing S, the first term of the second member of the
equation may be increased at will, and consequently the second term which is O₁
reduced as desired.
In this arrangement of apparatus the whole of the weight of superheated steam
does not affect the thermometer after superheating the saturated steam. A fraction
of this weight is employed in vaporizing the oil or hydrocarbon of any description
used as fuel. The said fraction is carried towards the combustion chamber through
an orifice of a sectional area=S¹. Let S be the sectional area of the orifice,
through which the mixture of superheated steam and saturated steam flows, the
temperature ¹, of which is indicated by the thermometer w.
In order to ascertain the weight of superheated steam which passes through the
passage S¹ it has been necessary to establish by an entirely new operation the
value of the counter pressure which is produced in the supei heater, and that in
function of S, S₁, S¹, and S. Let / represent the counter pressure.
The formula for the counter pressure h. will then be
+a
1+ (8+ S.) 0-375
a being the co-efficient of the dilatation of the superheated steam a= =0.003665,
and 0.375 expressing the increase of the height of the water for each degree for a
pressure slightly exceeding one atmosphere. For the practical adjustment of the
counter pressure S, S₁, are obtained from known and variable sections of the two
valves b, G, for the distribution of steam. Moreover S¹ and S¹ are varied by inter-
posing discs perforated with holes of varying section both in the passage of the
mixture of superheated with saturated steam, the temperature of which is indicated
by the thermometer, and in the passage of the superheated steam which is passing
direct to the combustion chamber. By this process the problem has been solved
of measuring with precision the temperature above that of boiling mercury by
means of a mercurial thermometer.
In order to obtain a constant and uniform full supply it is necessary that the
combustion chamber of the apparatus should be a source of uniform heat; this is
effected by regulating the amount of the various elements of combustion with
precision; moreover, this adjustment is checked by means of a special apparatus
indicating the temperature at all times.
The elements of combustion employed consist of the weight of hydrocarbon liquid,
and the weight of air introduced per second. In order to obtain the perfect
uniformity of these weights the liquid fuel is introduced through an apparatus
which is composed,-
First. Of a level regulator d, provided with an overflow.
Second. Of a graduated valve, similar to that shewn in Figures 6 and 7.
Third. Of a primary blower, delivering a known weight of saturated steam per
second at a known temperature T, and acting by a uniform propulsion.

page_text: Fourth. Of a second blower delivering a known weight of superheated steam per
second, at a known temperature 0, acting in a uniform manner by heating and
injection.
The level regulator d may be placed in communication either with the reservoir D of
hydrocarbon liquid or with a graduated tube w¹ of a section m. When the apparatus
is working the oil passes directly from the reservoir D to the level regulator d, but
when it is desired to measure the delivery of oil per second the communication
between the valve and the reservoir must be closed, and that between the graduated
tube filled with oil of a section = m opened. The level regulator is then
supplied by the volume delivered by this tube during a time = t, and as the flow
of the liquid is kept up by the overflow the volume of liquid delivered by the valvo
when open is equal to the volume delivered by the tube minus the volume over-
flowing from the level regulator, which is collected in a graduated guage glass
WARSAL E
This apparatus for measuring the delivery of an orifice under a uniform pressure
constitutes an important feature of the said Invention.
Moreover, if the area of the said orifice is changed the co-efficient of contraction
of the moving body of liquid may be determined without arresting the flow of the
said liquid.
The oil delivered by the measuring valve propelled by the saturated steam and
vapourized and injected by the superheated steam enters the combustion chamber
where it meets with the air requisite for its combustion. This air is conducted
through a metal tuyere c, perforated with holes c, and in which it is superheated
in its passage, as described, with reference to Figures 3, 4, and 5.
The weight of air thus introduced per second is determined with precision,
being supplied by the fan blower C, Figures 1 and 2, of regulated speed to a
gasometer C, where its pressure is made uniform, and delivered through the
regulating valve .
The proportion between the weight of the oil and of the hot air brought
together per second in the combustion chamber may be varied at pleasure, so
that either the complete combustion of the oil may be effected with a calculated
excess of air, or its incomplete combustion in known proportions and conditions
for the purpose of imparting either oxidising or reducing properties to the
gases resulting from such combustion.
In order to establish empirically the temperature of the combustion a given
weight of water per second=P is poured into the cast-iron box H', situato in the
passage of these gases, and where the liquid is divided on iron shavings.
The flow of this weight of water P is rendered uniform by the level regulator 11,
similar to that employed for the oil; it is so regulated that the steam obtained
from it is superheated to a temperature = T₁, lower than that of boiling mercury.
This temperature is indicated by a thermometer placed in a tube forming a
prolongation of the cast-iron box Ĥ¹.
-
It is evident that the caloric absorbed in evaporating and superheating the weight
of water P is taken from the caloric generated by the combustion (the weight p of
the gases resulting therefrom may be calculated as the weight of oil, air and steam
brought together per second is known. The mean specific heat = c may also be
ascertained by calculation).
Let represent the temperature of the water introduced, and the following
equation will be obtained

page_text: By changing the weight P, which becomes Pr, T,, will be made to change, which
will become Tj, and the following equation will be obtained·
-
-
←
-
Pr { 637) − ) + 0.4805 (Tj, — 100)} = p c (Œ¹ — Tj).
Dividing these equations member by member, there will be obtained,—
Dividing these equations member by member, there will be obtained,–
0¹
0'
T₁
637
-
Tj,
=
1637
+0.4805 (T-100
i+04805 (T-100
Whence the value ¹ is obtained.
The number of units of heat thus computed will be p c O¹, in order to obtain the
total amount of the caloric developed by the combustion it will be necessary to add
to it the amount of the caloric absorbed by the superheating of the weight p² of
steam, that is,-
P10 4805 (-T)}.
The said Invention provides the means for obtaining the following results,
namely:
First. A known weight of superheated steam, without admixture of gas, at the
temperature or O, at will.
Second. A known weight of superheated steam, at the temperature T', mixed
with the gases of combustion which may have been rendered oxidising or reducing
at will as the proportion of the weight of oil and of hot air brought together in the
combustion chamber can be changed at will.
This apparatus may be applied to all industries which require or are capable of
employing superheated steam.
Among these applications, the following may be specially mentioned :-
First. The manufacture of manure from leather, waste wool, horn, and other animal
substances; these substances, after treatment by superheated steam, yield (without
the employment of sulphuric acid or other chemical agents) a manure which is
pulverisable, soluble, and assimilable, and has not lost any of its constituent
nitrogen.
Second. The distillation of fatty substances with a view to the manufacture of
stearine, oleine, and the like. By employing the apparatus forming the object of
the said Invention the temperature may be brought entirely under control, and the
serious difficulties will be removed which have heretofore been experienced in the
distillation of these substances, whilst a uniform and superior yield will be obtained.
Third. In the metallurgical treatment of iron and other metals by employing at
will a constant or uniform temperature, with an oxidising or reducing atmosphere
Fourth. Dessications and evaporations in general which require to be effected at
a uniform temperature.
Fifth. The treatment of the various hydrocarbons, glycerine, oil, and analogous
viscous substances.
Sixth. The distillation of wood for the manufacture of pyroligneous acid.
The Invention is also applicable to the purposes of cremation.
The apparatus may be modified in its details without departing from the principle
of the said Invention.
Having now described and particularly ascertained the nature of the said Inven-
tion, and the manner in which the same is or may be used or carried into effect, I
would observe in conclusion that what I consider to be novel and original, and
therefore claim as the Invention secured to me by the herein-before in part recited
Letters Patent is,―
First. A superheater wherein the combustion chamber which produces the super-
heating is a source of heat for extraneous use, as well as of the heat necessary for
effecting the superheating, the temperature of the said chamber being determined
by the combustion in a unit of time of a known weight of liquid hydrocarbon
brought into contact with a known weight of air, all in the manner and by the aid
of apparatus, substantially as and for the purposes herein-before described.
Secondly. Determining the exact weight of steam passing through the superheater

page_text: during a unit of time, in the manner and by the aid of apparatus, substantially as
and for the purposes herein-before described.
Thirdly. Determining with precision the superheating temperature by means of
a mercurial thermometer, even when this temperature is greater than that of boiling
mercury, in the manner and by the aid of apparatus, substantially as and for the
purpose berein-before described.
Fourthly. Introducing into the gases resulting from the combustion and the
weight of which is ascertained, a known weight of water, which is at the same time
vaporised and superheated, thereby enabling the temperature of the said gases to be
determined by means of two consecutive experiments, in the manner and by the aid
of apparatus, substantially as and for the purposes herein-before described.
In witness whereof, I, the said John Henry Johnson, have to this my Specifi-
cation set my hand and seal, the Fifth day of June, One thousand eight
hundred and seventy-eight.
HAN
TATTNAAN