NEW OR IMPROVED MODES OF AND MEANS OR APPARATUS FOR UTILIZING THE POWER AND HEAT OF THE STEAM USED IN MOTIVE POWER ENGINES, AND FOR OTHER PURPOSES
Year: 1870

page_text: LETTERS PATENT to William Richard Middlemore Thomson, of the
City of Glasgow, in the County of Lanark, North Britain, Patent
Agent, for the Invention of "NEW OR IMPROVED MODES OF AND MEANS OR
APPARATUS FOR UTILIZING THE POWER AND HEAT OF THE STEAM USED IN
MOTIVE POWER ENGINES, AND FOR OTHER PURPOSES."-A communication
from abroad by Treat Timothy Prosser, of the City of Chicago, in
the State of Illinois, in the United States of America, Engineer.
Sealed the 31st December 1870, and dated the 1st October 1870.
PROVISIONAL SPECIFICATION left by the said William Richard
Middlemore Thomson at the Office of the Commissioners of Patents,
with his Petition, on the 1st October 1870.
I, WILLIAM RICHARD MIDDLEMORE THOMSON, of the City of Glasgow'
in the County of Lanark, North Britain, Patent Agent, do hereby declare
the nature of the said Invention for "NEW OR IMPROVED MODES OF AND
MEANS OR APPARATUS FOR UTILIZING THE POWER AND HEAT OF THE STEAM USED IN
MOTIVE POWER ENGINES, AND FOR OTHER PURPOSES," (a communication to me
from abroad by Treat Timothy Prosser, of the City of Chicago, in the

page_text: State of Illinois, in the United States of America, Engineer,) to be as
follows, that is to say :-
This said Invention has reference to an Invention communicated by
the said Treat Timothy Prosser to William Robert Lake, of 8, South-
ampton Buildings, London, and for which Royal Letters Patent were
granted to him entitled "Improvements in Apparatus for Generating
and Condensing Steam, and in Furnaces for Steam Generators, and for
other Purposes," dated the 28th April 1869, and numbered 1321.
And the object and advantages of this said Invention are by a
new or improved mode and means of treating or using steam and its
water of condensation at pressures by preference above that of the
atmosphere, to save and reuse nearly all the heat required to raise all the
steam at or to the pressure of the atmosphere, namely, the sum of the
latent and sensible heat therein at that pressure, and which has heretofore
been nearly all thrown away in all motive power steam engines, and in a
great many other operations where steam is used as a power producing
or heating medium up to the present time, and all which heat by this
Invention is utilized in addition to or together with all the power or heat
in the steam above or more than the said heat saved or that due to it
at the pressure of the atmosphere, and which has also heretofore been
utilized.
And this said Invention or the nature thereof consists in so con-
structing and arranging the parts and connections of steam generating
and condensing apparatus or steam boiler and condenser (in one or they
might be separate) so that the live steam generated in the boiler is a
conveyed to the engine or vessel where its power or heat is to be used
(as heretofore), and all the exhaust or used steam and condensed water
thereof and therefrom is then discharged or expanded and returned into
a large close condenser so formed (in one with or connected to the steam
generator) and considerably filled with large condensing surface tubes as 3
to condense all the steam by its expansion therein (under reduced
pressure though not in vacuum), and radiate its latent heat set free to
the surface of the " conducting tubes," with or having a close space
(within and between them and small concentric heat transmitting tubes)
filled with air or other receiving and conducting medium, and which 3
also receives and transmits the said heat to the surfaces of the internal
"heat tubes between the close space and the water, which finally
receives the said heat as it is circulating within or through them and the
"

page_text: steam generator. Thus the water within the steam boiler or generating
part of the apparatus receives back all the latent and sensible heat in
the steam due to the pressure maintained in the condenser, while the
water which finds its level at the bottom of the condenser and contains
the remainder of all the heat which was in the steam when it went into
the condenser, namely, the sensible heat due to the water condensed at
the said pressure within the condenser, is all drawn from the lower part
of the condenser and forced into the steam generator (by a feed pump
or other usual equivalent), consequently all the heat which was left
in the exhaust or used steam is thus by these said improvements returned
into the steam generator as well as all the water, which is thus
redistilled, and both thus used over and over again to assist in making
and keeping up the current of live steam required along with the heat
from the fuel used within the furnace of the boiler, which fuel by these
means is reduced to the minimum of producing or supplying only the
heat necessarily absorbed or utilized in power.
By the adoption of these improvements and improved means and
apparatus which form this said Invention, the conditions of construction,
arrangement, and action of which latter are herein-after more fully
described and referred to, no loss of heat taking place except that due to.
the usual outward radiation of heat from the surfaces of the vessels and
parts and the leakage of water at their pores or joints due to such
machines generally, and to be lessened and guarded against in the usual.
manner by heating jackets and non-conducting coverings and small fresh
supplies of water from time to time.
The mere returning of the water of condensation to the steam gene-
rator is not in itself new, but the producing or condensing of the water
from the steam under pressure in a close condenser (without the use of
jets or currents of cold water or air by what is termed direct or surface
condensation under vacuum) and the returning of it again to the
generator at the greater heat due to the pressure within this improved
condenser are considered quite new and form an important part of this
said Invention, and the construction and use of a condenser formed with.
one or more of the said concentric annular duplex condensing and heat
receiving, conducting, and concentrating tubes, the large one in contact
with the exhaust steam or water in the condenser and the small one in
contact with the water or steam in the generator (and which is termed
the "heat returning unit" of the apparatus or condenser) is also con-

page_text: sidered quite new and a most essential part of this said Invention. It
will be further seen therefore that not only is there this great saving of
fuel by these improvements commensurate to the production of all the
heat usually thrown away with the condensed steam or water and with
the heat absorbing water or air used for condensing the steam when
applied to motive power steam engines heretofore, but that a propor-
tionately less fire-grate heating surface and size of steam generator is
required, producing a corresponding saving in the first cost of these, and
all the price of maintaining them, and in steam engines of working and
keeping up air and circulating pumps for condensers worked under
vacuum, which is always difficult to produce and keep tight besides
absorbing much power, especially in high speed engines, and which are
all done away with by the adoption of these improvements.
And in order that the nature of this said Invention may be properly
understood it is advisable now to explain the several Figures on
the Sheet of Drawings which have been hereunto appended for that
purpose.
Figure 1 is a longitudinal vertical section of one construction and
arrangement of steam boiler or generator and new or improved condenser
combined, or a modification of a new or improved steam generating and
condensing apparatus, constructed in accordance with one modification
of the said Invention, and sufficient to show and describe its nature and
novelties, or the principle, application, and working thereof, and the
essential construction and arrangement of the parts of the apparatus for
performing the said purpose and saving of the heat of steam; Figures 2
and 3 are transverse sections of the same taken on the lines 1-1
and 2-2 respectively in Figure 1 through the steam boiler or gene-
rator and through the condenser and tubes; while Figures 4 and 5 are
respectively longitudinal and transverse sections of a single large outer
exhaust or "condensing tube" a and small internal water or heat tube b
fixed and jointed to each other at their ends c into the end plates of the
condenser e, so as to leave and form a close annular air space d along
the whole length and between the two tubes a, b, the whole forming
what is termed the "unit" of this said new or improved high-pressure
condensing regenerating steam boiler, as detached from Figure 1, but
shown to a large scale. The condenser proper is the large cylindrical
space e enclosed within the large outer central shell fand the two end
tube plates f¹,f¹, secured within it at f', in which plates f¹ and ends c

page_text: "
of all the duplex " units a, b, are fixed, so as to fill up a great part of
the condenser e, and leaving a sufficient available space e, forming the
condenser between and surrounding the outer condensing surfaces of all
the tubes a for the exhaust or used steam from the pipe g to expand
into and down to the pressure desired to be maintained while being
condensed, and giving a condensing and heat absorbing and conducting
surface equal to the whole circumferential area of all the large tubes a.
The steam boiler or generator A consists mainly of the two
spaces A', A", formed by the hollow semi-domed ends B', B", as its
shell, together with the ends of the body part f (which forms the shell
of the condenser also) attached by their end flanges at f". These
water or water and steam spaces A and A", which are joined together
by the circulating water or "heat tubes" 6 herein-before referred to,
with the steam dome C and steam receiver C³ connecting the two end
spaces A', A", from the steam generator A. The furnace or fire-box D
of the boiler A, which is shown of a strong vertical cylindrical form,
with hollow semi-domed ends D₁, D", is arranged or placed in the front
space A¹, having its grate D² below with ash-pit and air opening F
formed down through the lower dome D' and boiler dome B', while the
chimney D³ passing up from the dome D" through the steam dome C
and the fire doorway D' enters and is formed through the front end B₁
of the boiler: A safety valve C² and other steam boiler mountings would
be fitted thereto, and the live steam taken away by a branch E from the
top of the steam dome C to be used, as indicated by the black arrows,
all much as usual; and the exhaust or used steam is brought back, as,
say, after having done work in a high-pressure steam engine, through
the exhaust or return. pipes g to the condenser e, into which it expands
and condenses on the outer surface of the tubes a, to which it imparts
its heat set free by the said expansion and condensation, as indicated
by the red arrows, all as herein-after more fully explained, the con-
densed steam or water falling to the bottom of the condenser e, as at e',
from whence it is drawn as usual by a feed pump, injector, or other
steam boiler feeding apparatus through the pipe h, and thence forced into
the steam generator by the branch feed pipe h, as indicated by the blue
arrows, at the high temperature due to the pressure of the steam in
the condenser e, that is to say, the constant supply of heat or heat
current from the steam being condensed under pressure on the tubes a,
and within the new condenser e, although at a lower temperature and

page_text: "
pressure than the steam and water within the inner heat tubes band
steam generator A, and receive on the greater conducting and con-
centrating surface of each condensing tube a of the heat transmitting
." units of the apparatus or condenser, as shown detached in Figures 4
and 5, is greater in its power of radiation and concentration of the heat
rays inwards on the tubes b, and water in them and the steam gene-
rator A in the direction indicated by the red arrows, particularly in
Figure 5, than that of the more intense or greater heat of or in the
water or steam within or of the steam generator circulating in and
acting on and radiating outwards through the radiating surface of the
small tubes b either upon the said larger tubes a on the whole aggregate
area surface or proportional part thereof. Although on a mere first
reflection the foregoing statement may look hypothetical, that the
greater or more intense heat of the water within the steam boiler A,
and acting on the inside of the smaller tube b, would not radiate out-
wards more powerfully on the condensing tube a and exhaust steam in
the condenser e than the latter tube a with its lesser heat of the exhaust
steam in the condenser acting on it would do on the former tube b, it
is trusted that the following few explanatory statements and reasoning
will show that there is no anomaly in it, but that the simple facts of
the nature, working, and saving of the Invention are essentially as
stated. The steam boiler A is supposed to be made of the best malleable
iron, as also the tubes a and b, so that the latter will conduct the currents
or rays of heat from the condensed steam or water and steam of the steam
generator, as imparted to them respectively, at an equal or equivalent
rate from equal surfaces or proportionate of their surfaces.
Referring to Figures 4 and 5 it will be seen that the inside diameter of
each tube a of the duplex radiating and concentrating "units" is twice the
diameter of the outside of each tube b, and as circumferences are to each
other as their diameters it thus follows that the area of the tubes a will
be double the area of the tubes in their circumferential radiating
surface respectively; and as their transverse area or measure of capacity
is proportional to the square of their diameter it follows that the close
space or air chamber d fulfils the condition of the law of radiation of
heat, namely, that the temperature of radiating heat, or the radiations
of heat, diminish in proportion to the square of the distance, or in pro-
portion to its expansion; and, vice versa, on the other hand, it is
increased in proportion to its concentration minus the quantity absorbed.

page_text: by the medium through which it passes. Thus if the heat rays are
expanded, say, from the tube b, Figure 5, so as to fall on the tube a, say,
of double the area of the tube b, from which they proceed, the heat
effect will necessarily be only one-half; if they fall upon three times the
area one-third the effect, and so on proportionately; and conversely,
when the radiating rays of heat from a larger area or surface, as, say,
from the large tube a, are concentrated upon a smaller surface, as,
say, upon the tube b, the heat is correspondingly increased; as, for
example, if the heat radiated from two feet of area is concentrated
upon one foot of area it will be evident that it will contain double the
quantity of heat per equal area, and so on in proportion to the difference
of area or concentration of the rays of heat. Thus it will be evident
that the condensing tubes a will radiate twice the quantity of heat
upon the tubes b inwards that the tubes will radiate outwards
upon the tubes a, the tubes a being twice the diameter and area of the
tubes b.
The object of filling the close annular chamber d of the "units,"
between the tubés a and b, Figure 4 and 5, with air is to have a
medium that will permit the said double radiation of heat to pass freely
through it without obstruction, and being but a moderate or poor
conductor of heat it will not interchange rapidly by contact. This
chamber is a most essential part of the Invention in producing the
cross radiation from the two sets of condensing and heat tubes a, b,
respectively, and further materially assists the condensation of the
5 exhaust steam in the condenser by the greater quantity of heat rays
passing in from the larger tubes a, becoming hotter as they meet the
smaller tubes b than the heat within the steam boiler A, and by the heat
rays from the lesser tubes 6 radiating outwards and becoming colder, so
tending to draw the heat from the condenser e and condensing tubes a,
0 thus together with the pressure of steam within the condenser e pro-
ducing a rapid condensation of the exhaust steam therein and current
of the latent heat set free thereby on the tubes a towards the water
within the heat tubes 6 and boiler A. It is also essential to arrange the
tubes a and b in this manner to obtain the said necessary larger area
5 of the conducting tubes a in proportion to the tubes 6, and to give the
said interchange of radiation and greater or more rapid current of the
heat rays inwards than outwards, all as stated. It will be evident that
this difference of diameter and area of the tubes a over that óf thể

page_text: tubes 6 may be increased by this concentric arrangement to any degre
desired, as two, three, four, five, or six times that of b, when they wil
radiate and concentrate the heat transmitted to them with the said
proportionally greater power, or, speaking of heat as rays, with a pro
portionally greater number of these heat rays or quantity of heat upon
the small tubes to the said difference of their area surface; and as
these tubes 6 are in contact with the water within these and the boiler A
it will receive back the said lateral heat, so as to produce or assist in
producing new live steam therefrom and therein over and over again;
and this difference of the diameter and circumference of the tubes a
and 6 is extended until it, as explained, is able to condense all the
exhaust steam passed through the engine and cylinder into the con-
denser e. The tubes a being used to produce condensation, and to return
the heat liberated thereby to the heat tubes b, and as the heat liberated
by condensation at atmospheric pressure, calling the sum of steam heat
1200° Fahrenheit, would be about 990°, or, say, in round numbers, 1000°,
supposing the utilization and loss of heat by work done, leakage, and
radiation to be equal to twenty per cent. of that of all the steam used
in the engine cylinder it follows that the exhaust steam will contain
cighty per cent. or four-fifths of the heat of all the steam that is admitted
to the engine cylinder, and as the steam condensed or water liberated
or formed by the condensation of the steam in the condenser would
contain heat equal to one-fifth of that contained in the exhaust steam,
and as this heat is returned with the water to the live steam boiler A by
feeding apparatus, as herein-before stated, the quantity of heat remaining
to be returned by radiation through the "unit" tubes a, b, is fully
equal to three-fifths of that contained in the steam entering the engine
cylinder. Suppose the steam is carried at a pressure of fifty pounds per
square inch in the boiler and engine, the temperature of steam at that
pressure being (283°) Fahrenheit, two hundred and eighty-three degrees, a
and the temperature of the water in the heat tubes 6 the same, and
that of the quantity of heat radiated be represented by the temperature
(283°) two hundred and eighty-three degrees, as this heat will be dis-
tributed over double the area its heat effect will be on an area equal to
that from whence it radiated only one-half of (283°) two hundred and 3
eighty-three degrees, or one hundred and forty-one and a half degrees,
141.5°. Suppose the pressure of the exhaust steam to be fifteen pounds
(15 lbs.) per square inch, with a temperature corresponding thereto of
ay (251.5°) two hundred and fifty-one and a half degrees, and as these

page_text: tubes a have double the surface of the heat tubes b, and as the radiations
therefrom are concentrating upon an area only one-half as large as the
area radiated from, it becomes evident that the heat effect will be double,
or (251-5°) two hundred and fifty-one and a half degrees from double
the area will equal (251.5°×2=503°) two hundred and fifty-one and a
half multiplied by two, equal to five hundred and three degrees. Now
as (283°) have been radiated from the same area that received the 503°
it follows that the heat effect produced will be (503°-283°=220°) five
hundred and three degrees, minus two hundred and eighty-three degrees,
equal to two hundred and twenty degrees. And as (220°) two hundred
and twenty degrees is the excess of radiation it follows that that is the
quantity of heat returned to the boiler (and of the heat in the steam
condensed); and as it is designed to return all the heat possible in this
way, and been herein-before shown approximately that all the heat that
can thus be returned is only three-fifths of that entering the cylinder,
and as one-fifth is returned with the water, making (3) four-fifths, it
will be evident that only one-fifth remains to be furnished under these
conditions by the fire, consequently the fire heating surface grate and
fire fuel may all be reduced to () one-fifth of that required by the
ordinary modes and means of operating steam engines, and of using
and treating exhaust steam generally.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Richard Middlemore Thomson in the
Great Seal Patent Office on the 28th March 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
RICHARD MIDDdlemore Thomson, of the City of Glasgow, in the County
of Lanark, North Britain, Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the First day of October, in the year
of our Lord One thousand eight hundred and seventy, in the thirty-
fourth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said William Richard Middlemore Thomson, Her
special licence that I, the said William Richard Middlemore Thomson,
my executors, administrators, and assigns, or such others as I, the said
William Richard Middlemore Thomson, my executors, administrators,

page_text: and 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 "NEW OR IMPROVED MODES OF AND MEANS
OR APPARATUS FOR UTILIZING THE POWER AND HEAT OF THE STEAM USED IN MOTIVE
FOWER ENGINES, AND FOR OTHER PURPOSES," the same is a communication
made to him from abroad by Treat Timothy Prosser, of the City of Chicago,
in the State of Illinois, in the United States of America, Engineer, upon
the condition (amongst others) that I, the said William Richard Middle-
more Thomson, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and seals, 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 William Richard Middlemore
Thomson, do hereby declare the nature of my said Invention, and in
what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement in writing, reference
being had to the accompanying Drawings, and to the letters and figures.
marked thereon, that is to say :-
My said Invention has reference to an Invention communicated by
the said Treat Timothy Prosser to William Robert Lake, of 8, South-
ampton Buildings, London, and for which Royal Letters Patent werc
granted to him entitled "Improvements in Apparatus for Generating
and Condensing Steam, and in Furnaces for Steam Generators, and for
other Purposes," dated the 28th April 1869, and numbered 1321.
And the object and advantages of this said Invention are by a new or
improved mode and means of treating or using steam and its water of
condensation at pressures by preference above that of the atmosphere,
to save and reuse nearly all the heat required to raise all the steam at
or to the pressure of the atmosphere, namely, the sum of the latent and
sensible heat therein at that pressure, and which has heretofore been
Dearly all thrown away in all motive-power steam engines, and in a
great many other operations where steam is used as a power producing
or heating medium up to the present time, and all which heat by this
Invention is utilized in addition to or together with all the power or

page_text: heat in the steam, above or more than the said heat saved, or than
that due to it at the pressure of the atmosphere, and which has
also heretofore been utilized.
And this my said Invention or the nature thereof consists in so
constructing and arranging the parts and connections of steam gene-
rating and condensing apparatus, or steam boiler and condenser (in one
or they might be separate) so that the live steam generated in the boiler
is conveyed to the engine cr vessel where its power or heat is to be used
(as heretofore) and all the exhaust or used steam and condensed water
thereof and therefrom is then discharged or expanded and returned into
a large close condenser so formed (in one with or connected to the steam
generator) and considerably filled with large condensing surface tubes as
to condense all the steam by its expansion therein (under reduced
pressure, though not in vacuum) and radiate its latent heat set free to
the surface of the " conducting tubes," with or having a close space
(within and between them and small concentric heat transmitting tubes)
filled with air or other receiving and conducting medium, and which also
receives and transmits the said heat to the surfaces of the internal "heat
tubes" between the close space and the water, which finally receives the
said heat as it is circulating within or through them and the steam
generator. Thus the water within the steam boiler or generating part
of the apparatus receives back all the latent and sensible heat in the
steam due to the pressure maintained in the condenser, while the water
which finds its level at the bottom of the condenser and contains the
remainder of all the heat which was in the steam when it went into the
condenser, namely, the sensible heat due to steam or water condensed
at the said pressure within the condenser is all drawn from the lower
part of the condenser and forced into the steam generator (by a feed
pump or other such usual equivalent), consequently all the heat which
was left in the exhaust or used steam is thus by these said improve-
ments returned into the steam generator, as well as all the water which
is thus redistilled, and both thus used over and over again to assist in
making and keeping up the current of live steam required along with
the heat from the fuel used within the furnace of the boiler; which fuel
by these means is reduced to the minimum of producing or supplying
only the heat necessarily absorbed or utilized in power.
By the adoption of these improvements and improved means and
apparatus which form my said Invention, the conditions of construction,

page_text: arrangement, and action of which latter will be herein-after more fully
described and referred to, no loss of heat taking place except that due to
the usual outward radiation of heat from the surfaces of the vessels and
parts, and the leakage of water at their pores or joints due to such
machines generally, and to be lessened and guarded against in the usual
manner by heating jackets and non-conducting coverings and small
fresh supplies of water from time to time.
66
The mere returning of the water of condensation to the steam generator
is not in itself new, but the producing or condensing of the water from
the steam under pressure in a close condenser (without the use of jets or
currents of cold water or air by what is termed direct or surface con-
densation under vacuum) and the returning of it again to the generator
at the greater heat due to the pressure within this improved condenser
are considered quite new, and form an important part of this my said
Invention; and the construction and use of a condenser formed with one
or more of the said concentric, annular, duplex condensing and heat
receiving, conducting, and concentrating tubes, the large one in contact
with the exhaust steam or water in the condenser, and the small one in
contact with the water or steam in the generator (and which I term the
heat returning unit" of the apparatus or condenser) and also consider
quite new and a most essential part of this my said Invention. It will
be further seen, therefore, that not only is there this great saving of
fuel by these improvements commensurate to the production of all the
heat usually thrown away with the condensed steam or water, and with
the Leat absorbing water, or air used for condensing the steam, when
applied to motive-power steam engines heretofore; but that a pro-
portionately less fire-grate heating surface and size of steam generator
is required, producing a corresponding saving in the first cost of these,
and all the price of maintaining them, and in steam engines, of work-
ing and keeping up air and circulating pumps for condensers worked
under vacuum, which is always difficult to produce and keep tight
besides absorbing much power, especially in high speed engines, and
which are all done away with by the adoption of these my improvements.
And in order that my said Invention may be properly understood and
performed or put into practice, I will now proceed to describe the several
illustrative Figures upon the Sheet of explanatory Drawings, which I
have hereunto appended for the purpose of showing the best modifi-
cations and means which I am at present aware of, under which my

page_text: improvements may be judiciously carried out in practice, the same
letters being employed to indicate the same or similar parts in all
the Figures.
Figure 1 is a longitudinal vertical section of one construction and
arrangement of steam boiler or generator and new or improved con-
denser combined, or a new or improved steam generating and condensing
apparatus, constructed in accordance with one modification of my said
Invention, and sufficient to show and describe its nature and novelties,
or the principle, application, and working thereof; and the essential
construction and arrangement of the parts of the apparatus for per-
forming the said purpose, and saving of the heat of steam; Figures 2
and 3 are transverse sections of the same taken on the lines 1-1, and 2-2,
respectively in Figure 1, through the steam boiler or generator, and
through the condenser and tubes, while Figures 4 and 5 are respectively
longitudinal and transverse sections of a single large outer exhaust or
condensing tube a, and small internal water or heat tube fixed and
jointed to each other at their ends c into the end plates f¹ of the con-
denser e, so as to leave and form a close annular air space d along the
whole length and between the two tubes a, b, the whole forming what I
termed a "unit" of this said new or improved high-pressure condensing
regenerating steam boiler, as detached from Figure 1, but shown to a
large scale.
"
Figures 6 and 7 are a horizontal and a transverse section respectively
of a part of another construction and arrangement of the duplex con-
densing and heat tubes or "units" (a, b,) as detached and somewhat
different from that shown in Figures 1 to 5, being in the form of rows
or sets of duplex globes a*, 6*, connected by necks or tubes at a and b
throughout.
"
Referring to Figures 1 to 5 the condenser proper is the large
cylindrical space e enclosed within the large outer central shell f and
the two end tube plates f¹, f¹, secured within it at f², in which plates f¹
the ends c of all the duplex " units a, b, are fixed, so as to fill up a
great part of the condenser e, and leaving a sufficient available space e
forming the condenser between and surrounding the outer condensing
surfaces of all the tubes a for the exhaust or used steam from the pipe g
to expand into and down to the pressure desired to be maintained while
being condensed, and giving a condensing and heat absorbing and
conducting surface equal to the whole circumferential area of all the

page_text: large tubes a. The steam boiler or generator A consists mainly of the
two spaces A', A", formed by the hollow semi-domed ends B¹, B", as its
shell, together with the ends of the body part f (which forms the shell of
the condenser also) attached by their end flanges at f"; these water or
water and steam spaces A¹ and A", which are joined together by the
circulating water or "heat tubes" 6 herein-before referred to with the
steam dome C and steam receiver C', connecting the two end spaces
A', A", form the steam generator A. The furnace or fire-box D of the
boiler A, which is shown of a strong vertical cylindrical form with hollow
semi-domed ends D', D", is arranged or placed in the front space A¹,
having its grate D² below, with ash-pit and air opening F formed down
through the lower dome D' and boiler dome B', while the chimney D³
passing up from the dome D" through the steam dome C and the fire
doorway D' enters and is formed through the front end B' of the boiler.
A safety valve C and other steam boiler mountings would be fitted
thereto, and the live steam taken away by a branch E from the top
of the steam dome C to be used, as indicated by the black arrows, all
much as usual, and the exhaust or used steam is brought as, say, after
having done work in a high-pressure steam engine, through the exhaust
or return pipes to the condenser e, into which it expands, and
condenses on the outer surface of the tubes a, to which it imparts its
heat set free by the said expansion and condensation, as indicated by
the red arrows, all as herein-after more fully explained, the condensed
steam or water falling to the bottom of the condenser e, as at e¹, from
whence it is drawn, as usual, by a feed pump, injector, or other steam
boiler feeding apparatus through the pipe h, and then forced into the
steam generator by the branch feed pipe ¹, as indicated by the blue
arrows, at the high temperature due to the pressure of the steam in the
condenser e, that is to say, the constant supply of heat or heat current
from the steam being condensed under pressure on the tubes a and
within the new condenser e, although at a lower temperature and
pressure than the steam and water within the inner heat tubes b and
steam generator A, and received on the greater conducting and con-
centrating surface of each condensing tube a of the heat transmitting
units of the apparatus or condenser, as shown detached in Figures 4 a
and 5, is greater in its power of radiation and concentration of the heat
rays inwards on the tubes band water in them and the steam generator A
in the direction indicated by the red arrows, particularly in Figure 5,
than that of the more intense or greater heat of or in the water or steam

page_text: within or of the steam generator circulating in and acting on and
radiating outwards through the radiating surface of the small tubes b,
either upon the said larger tubes a on the whole aggregate area surface
or proportional part thereof. Although on a mere first reflection the
foregoing statement may look hypothetical, that the greater or more
extensive heat of the water within the steam boiler A and acting on the
inside of the small tube b would not radiate outwards more powerfully
on the condensing tube a and exhaust steam in the condenser e than the
latter tube a with its lesser heat of the exhaust steam in the condenser
acting on it would do on the former tube b, I trust that the following
few explanatory statements and reasoning will show that there is no
anomaly in it, but that the simple facts of the nature, working, and
saving of my said Invention are essentially as stated. The steam boiler A
is supposed to be made of the best malleable iron, as also the tubes a
and b, so that the latter will conduct the currents or rays of heat from
the condensed steam or water and steam of the steam generator, as
imparted to them respectively at an equal or equivalent rate from equal.
surfaces or proportionate to their surfaces.
Referring to Figures 4 and 5 it will be seen that the inside diameter
of each tube a of the duplex radiating and concentrating "units" is
twice the diameter of the outside of each tube b; and as circumferences
are to each other as their diameters it thus follows that the area of the
tube a will be double the area of the tubes in their circumferential
radiating surface respectively, and as their transverse area or measure of
capacity is proportional to the square of their diameter, it follows that
the close space or air chamber d fulfils the conditions of the law of
radiation of heat, namely, that the temperature of radiating heat or the
radiations of heat diminish in proportion to the square of the distance or
in proportion to its expansion, and vice versa, on the other hand, it is
increased in proportion to its concentration minus the quantity absorbed
by the medium through which it passes; thus if the heat rays are
expanded, say, from the tube b, Figure 5, so as to fall on the tube a, say,
of double the area of the tube b from which they proceed, the heat effect
will necessarily be only one-half; if they fall upon three times the area
one-third the effect, and so on proportionately, and conversely when
the radiating rays of heat from a larger area or surface as, say, from the
large tube a, are concentrated upon a smaller surface, as, say, upon the

page_text: tube b, the heat is correspondingly increased; as, for example, if the heat
radiated from two feet of area is concentrated upon one foot of area it
will be evident that it will contain double the quantity of heat per equal
arca, and so on in proportion to the difference of area or concentration of
the rays of heat. Thus it will be evident that the condensing tubes a
will radiate twice the quantity of heat upon the tubes b inwards that
the tubes 6 will radiate outwards upon the tubes a, the tubes a being
twice the diameter and area of the tubes b. The object of filling the
close annular chamber d of the "units" between the tubes a and b,
Figures 4 and 5, with air is to have a medium that will permit the said
double radiation of heat to pass freely through it without obstruction,
and being but a moderate or poor conductor of heat, it will not inter-
change rapidly by contact. This chamber d is a most essential part of
my said Invention in producing the cross radiation from the two sets of
condensing and heat tubes a, b, respectively, and further materially
assists the condensation of the exhaust steam in the condenser e by the
greater quantity of heat rays passing in from the larger tubes a becoming
hotter as they meet the smaller tubes 6 than the heat within the steam
boiler A, and by the heat rays from the lesser tubes 6 radiating outwards
and becoming colder, so tending to draw the heat from the condenser e
and condensing tubes a, thus together with the pressure of steam within
the condenser e, producing a rapid condensation of the exhaust steam
therein, and current of the latent heat set free thereby on the tubes a
towards the water within the heat tubes and boiler A. I arrange the
tubes a and b in this manner to obtain the said necessary larger area of
the condensing tubes a in proportion to the tubes b, and to give the said
interchange of radiation and greater or more rapid current of the heat
rays inwards than outwards, all as stated. It will be evident that this
difference of diameter and area of the tubes a over that of the tubes b
may be increased by this concentric arrangement to any degree desired,
as two, three, four, five, or six times that of b, when they will radiate
and concentrate the heat transmitted to them with the said proportionally
greater power, or speaking of heat as rays with a proportionally greater
number of these heat rays or quantity of heat upon the small tubes 6 to
the said difference of their area surface, and as these tubes 6 are in
contact with the water within these and the boiler A it will receive back
the said latent heat, so as to produce or assist in producing new live
steam therefrom and therein over and over again; and this difference of

page_text: the diameter and circumference of the tubes a and b is extended until it
as explained is able to condense all the exhaust steam passed through
the engine and cylinder into the condenser e. The tubes a being used
to produce condensation and to return the heat liberated thereby to the
heat tubes b, and as the heat liberated by condensation at atmospheric
pressure, calling the sum of steam heat 1200° Fahrenheit, would be
about 990°, or, say, in round numbers 1000°, supposing the utilization
and loss of heat by work done, leakage, and radiation to be equal to
twenty per cent. of that of all the steam used in the engine cylinder, it
follows that the exhaust steam will contain eighty per cent. or four-fifths
of the heat of all the steam that is admitted to the engine cylinder; and
as the steam condensed or water liberated or formed by the condensation
of the steam in the condenser would contain heat equal to one-fifth of
that contained in the exhaust steam, and as this heat is returned with the
water to the live steam boiler A by feeding apparatus, as herein-before
stated the quantity of heat remaining to be returned by radiation
through the "unit" tubes a, b, is fully equal to three-fifths of that
contained in the steam entering the engine cylinder. Suppose the steam
is carried at a pressure of fifty pounds per square inch in the boiler and
engine, the temperature of steam at that pressure being (283° Fahrenheit)
two hundred and eighty-three degrees, and the temperature of the water
in the heat tubes 6 the same, and that of the quantity of heat radiated
be represented by the temperature (283°) two hundred and eighty-three
degrees, as this heat will be distributed over double the area its heat
effect will be on an area equal to that from whence it radiated, only one-
half of (283°) two hundred and eighty-three degrees, or one hundred
and forty-one and a half (141·5°). Suppose the pressure of the
exhaust steam to be fifteen pounds (15 lbs.) per square inch, with a
temperature corresponding thereto of, say, (251.5°) two hundred and
fifty-one and a half degrees, and as these tubes a have double the surface
of the heat tubes b, and as the radiations. therefrom are concentrating
upon an area only half as large as the area radiated from, it becomes
evident that the heat effect will be double or (251.5°) two hundred and
fifty-one and a half degrees from double the area, will equal (251.5°×2
=503°) two hundred and fifty-one and a half, multiplied by two, equal
to five hundred and three degrees. Now as (283°) have been radiated-
from the same area that received the 503°, it follows that the heat effect
produced will be (503°-283°=220°) five hundred and three degrees,
minus two hundred and eighty-three degrees, equal to two hundred and

page_text: twenty degrees. And as (220°) two hundred and twenty degrees is the
excess of radiation it follows that that is the quantity of heat returned
to the boiler (and of the heat in the steam condensed), and as it is
designed to return all the heat possible in this way, and having herein-
before shown approximately that all the heat that can thus be returned is
only three-fifths of that entering the cylinder, and as one-fifth is returned
with the water, (4) four-fifths, it will be evident that only one-fifth
remains to be furnished under these conditions by the fire, consequently
the fire heating surface, grate, and fire fuel may all be reduced to
(3) one-fifth of that required by the ordinary modes and means of
operating steam engines, and of using and treating exhaust steam
generally.
Although throughout this Specification and the references to the
Drawings Figures 1 to 5 I have only described and shown the duplex
units a, b, (Figures 4 and 5) as formed of parallel tubes, it will be quite
understood by practical engineers that they may also be constructed in a
conical form, or in a series of globular structures a*, 6*, connected by
tubular necks a, b, as shown in Figures 6 and 7, the arrows indicating
the action or radiation of the heat in these Figures, substantially as
described in reference to Figures 4 and 5, except that at the spherical a
parts a, b, the rays of heat will act on their respective surfaces in the
proportion of the square of their diameters, and with a corresponding
concentrative or dispersive effect respectively. The long red arrows
indicate the inward radiating direction of the currents of exhaust steam
to and from the condensing tubes, as a and a*, upon and through the
inner heat tubes b, and the small black darts indicate the outward
radiation of the heat from the water tubes 6 and 6*, particularly shown
in the large detached Figures 4 to 7 of the condensing and heat trans-
mitting units. I have shown the parallel tubes or units a, b, as applied
in the modification shown and described in reference to Figures 1 to 5,
because I believe they are more simply, cheaply, and easily constructed
than the conical, globular, or other forms of tubes or vessels which would
fulfil the herein-before stated conditions which these parallel tubes
sufficiently do. Although air has been described as preferable for filling
the annular space d of the "units," it is to be understood that other
fluids or gases may be employed for that purpose as the heat cross
radiating medium, such as oxygen, hydrogen, and nitrogen, which may
be named as the next best mediums for the purpose to that of air.

page_text: Although the heat transmitting space or annular chamber d between the
tubes a, b, has been herein described as close, it is to be understood that
a certain proportion of the fluid medium used in these spaces, as the air,
may be admitted thereto, and as heated be taken or conducted by
regulating inlet and outlet valves in cases when it is desired to utilize
the heat therefrom otherwise than by passing it through the heat tubes 6
into the generator A direct, as by using a proportion of this hot air for
supplying the furnace and accelerating its draught, and these inlet and
escape valves, when fitted to the close spaces d as named, a portion of the
air may be allowed to escape (as at starting) when it has become
equalized or surcharged with heat by stopping the working of the con-
denser for a time. And when water gets into the annular spaces d
by a defective joint or otherwise it also can be allowed to escape by
the said valves, or by a pin as c¹ at the ends c of the “units," which
would allow the defective part to be detected and repaired at once and
simply without loss of time. The condenser e would be fitted with a
blow-off valve loaded or regulated to the pressure at which condensation
was to take place in it, to allow the steam or air to blow off when they
by any means got into it or their pressure and heat rose above that
at which condensation would take place in the condenser by the inward
radiation of heat to the water within the steam generator A. It will be
understood that the one side of the end plates f' of the condenser e or
the outer exposed surfaces of the boiler, steam pipes, or other parts may
have a covering of bad or non-heat conducting material to prevent loss
from radiation, and that a little new or additional fresh water would
from time to time be required to be fed into the generator A through
the pipe h¹ along with the condensed steam or water e¹ to supply or
make up for the loss of steam or water at the valves, stuffing boxes, and
joints during the working of steam engines fitted with this new steam
generating and condensing apparatus.
Having thus particularly described the nature of my said Invention,
and the manner in which the same is or may be used or carried into
effect, I may observe in conclusion that I do not confine or restrict
myself to the precise details, modifications, or arrangements which I
have had occasion to describe, delineate, and refer to, as many variations
of and from these may be made without departing from the main or
essential features of my said Invention; neither do I claim to have

page_text: invented the form and construction of some of the minor parts, or their
modes of attachment, which I have had occasion to describe and refer to
as such may have been used for other mere ordinary steam boilers or
furnaces, except in so far as these have essential reference to or form
part of my said Invention; but what I consider novel and original, and
therefore claim as the Invention secured to me by the herein-before in
part recited Letters Patent is, -
First. The construction and arrangement of the parts of a combined
or connected steam generating and condensing apparatus for condensing
and resecuring or abstracting all the unused and "latent" heat of
exhaust or used steam from steam engine cylinders and other vessels,
and returning the same to the steam boiler or generator to assist in
generating fresh live steam therein along with the heat from ordinary
fuels and furnaces, all substantially in the new or improved manner
herein described and shown in the accompanying Drawings.
Second. The construction of a close condenser as e directly connected
to a steam generator A for condensing the exhaust and used steam from
steam engine cylinders and other vessels under pressures above that of
the atmosphere, so as to return all the heat and water of condensation
therefrom and thereto respectively, all substantially in the new or
improved manner herein described.
«
Third. The construction, arrangement, and use of close condensers
with or having one or more of the arrangements of duplex tubes or
units," as a, b, with an enclosed space between them for condensing
the exhaust and used steam from steam engine cylinders and other
vessels, and for receiving, radiating, and concentrating the latent heat
thereof and therefrom into the water within the steam generator, all
substantially as herein described.
Fourth. The concentrating of the radiant heat of used or exhaust
steam from steam engine cylinders and other vessels by concave surfaces
or tubes, so as to concentrate a larger amount of heat upon a given
smaller convex surface or tube than would radiate from it (or a like
amount of surface) at a given temperature, thus making it a heating or
heat transmitting medium to the water, substantially in the manner and
for the purpose herein described.
Fifth. The construction and use of duplex tubes or “units,” as a, b,
for condensing the exhaust steam from steam engine cylinders and other

page_text: vessels, and radiating its latent heat under pressure into the steam
generator, substantially in the new or improved manner herein described.
In witness whereof, I, the said William Richard Middlemore
Thomson, have hereunto set my hand and seal, this Twenty-
seventh day of March, in the year of our Lord One thousand
eight hundred and seventy-one.
Witness,
JOHN THOMSON,
Patent Agent,
20, Buchanan Street,
Glasgow.
W. R. M. THOMSON.
(L.S.)