SUBPACE CONDENSER APPLICABLE TO STEAM ENGINES AND OTHER PURPOSES
Year: 1857

page_text: LETTERS PATENT to James M. Miller, of Washington, in the County of
Washington, D. C., United States of America, for the Invention of
PROVISIONAL SPECIFICATION left by the said James M. Miller at the
Office of the Commissioners of Patents, with his Petition, on the 8th
September 1857.
I, JAMES M. MILLER, of Washington, in the County of Washington, D. C.,
United States of America, do hereby declare the nature of the Invention
for "SUBPACE CONDENSER APPLICABLE TO STEAM ENGINES AND OTHER PURPOSES,"
to be as follows:
My improvements refer to the arrangement and construction of the metallic
surfaces for condensing steam and heating the water of condensation, by which
more perfect results than heretofore obtained are produced.
The following is a description of the construction, which may, however, be
modified in some of the details and in general configuration, as will be evident
to any competent engineer, while in all cases the main principle of a central
surface.condenser, with lateral branching tubes and recesses, in one or more
series, is maintained. I form oblong sections of cast iron or other suitable
metal, upon which a series of lateral tubes may be cast, opening into the
centre section, or holes may be formed in the section, and the tubes otherwise

page_text: affixed thereto by brazing, or screwing, or bolting; these tubes, which form
recesses on either side, I form in a peculiar manner by attaching another tube
within it, the attachment being at the extreme outer end of the first-mentioned
tube, by which an annular space is left between the tubes opening into the
centre section; a second inner tube may be affixed to the inner end of the
second tube, and so on for other tubes to any convenient number, placed one
within another and attached at opposite ends alternately, so as to form a series
of concentric recesses of any number, from one upwards, to the maximum
point of subdivision, leaving on the outside on both sides of each of these
recesses a water space for the outside water of condensation. The several tubes
should be somewhat conical, and the innermost one closed at its inner end.
The attachments of the tubes may be made by screws, or by any other known
and sufficient means, depending upon the material of which the tubes are
made; this may be iron or other metal, cast or wrought. A series of sections
like that just described, may be bolted together by flanches on the upper or
lower edges, or otherwise firmly attached, the joints being packed, and joints
broken by a projection from the top of the sections entering the bottom of the
one above it. A series of the above may be so arranged as to have their
lateral tubes nearly fill the interior of an outer case that surrounds them. This
surrounding case may be made of thin metal, and contains the water used for
condensing the steam. The sections thus described rest upon a plate at the
bottom, which covers another chamber below, in which are a series of coils of
pipe, one coil for each section; these coils of pipe pass through the plate and.
connect with the bottom of the section. The coil in the lower chamber com-
municates with the pump well, thus uniting the pumps with the interior of the
sections; the lower chamber is freely supplied with cold water from the
outside; the cold water also surrounding the pump well and valves. Instead
of the usual large and powerful air pump, I perfer to use two small pumps,
which I find sufficient for the purpose; these pumps draw the condensed
water from the coils and force it into the case surrounding the sections, which
is filled with water, and from whence the water passes to the boiler. This
water surrounding the sections I keep at a very high degree of heat, up to
nearly the boiling point at the top, and produce a constantly ascending column
by the injection from the pumps, and the large globules of heated water pro-
duced by the current from the pumps and from the surface of the condenser,
which is more active in consequence of the surface water being heated.
It may be here proper to remark, that I have, by careful experiment, found
that warm water extracts the heat from steam more rapidly than cold water
does. The water in the upper section of the case is hot, the condensed steam

page_text: passing through the pumps into an air chamber situated at the lower part of
the upper chamber or condenser case where the air and permanent gases are
separated, and occasionally let off through a stop-cock; or instead of this air
chamber being at this point it may be at the top of the condenser case, whence
the heated water passes through a pipe to the boiler; thus it will be seen, that
nothing but pure water ever comes in contact with the heated surface of the
condenser tubes, either outside or inside, and pure water alone is supplied to
the boiler. Tlie steam from the engine or other source passes into the interior
of the sections of the condenser through the induction or steam pipe; just
before it enters the condenser it enters a receptacle under au evaporator that
is employed to supply the waste occasioned by leakage or otherwise of the
boiler and machinery; this receptacle is formed of short upright tubes, the
evaporator is filled from the outside, with water from any source, impure or
otherwise; a pipe leads from the top of the evaporator down into the steam
induction pipe, and all the vapour generated in the evaporator is conveyed by
it into the condenser with the steam from the engine, and adds to the supply,
and makes up for the deficiency made by leakage, as before named. The
contents of the evaporator can be occasionally blown off when it gets.foul.
SPECIFICATION filed by the said James M. Miller in the Great Seal Patent
Office, on the 8th March 1858, in pursuance of the conditions of the
Letters Patent, and of an Order of the Lord Chancellor, dated 20th.
March 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
M. MILLER, of Washington, in the County of Washington, D. C., United
States of America, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighth day of September, in the year of our Lord
One thousand eight hundred and fifty-seven, in the twenty-first year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said James M. Miller, Her special licence, that I, the said James M.
Miller, my executors, administrators, and assigns, or such others as I, the said
James M. Miller, my executors, administrators, 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 "SURFACE CONDENSER.

page_text: APPLICABLE TO STEAM ENGINES AND OTHER PURPOSES," upon the condition (amongst
others) that I, the said James M. Miller, 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 Inven-
tion, 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 James M. Miller do hereby declare
the nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof, that is to say:
Fig. 1 is an elevation of the exterior of the condenser, showing the air
pumps; Fig. 2 is a vertical section; Fig. 3 is a top plan in section, showing
the arrangement of the tubes; Fig. 4 is a plan of the coil at the bottom of
'the condenser connecting with the air pumps; Fig. 5, a portion of one section
of the condenser with one of the lateral tubes or recesses cut through its axis.
My improvements refer to the arrangement and construction of the metalic
surfaces for condensing steam and heating the water of condensation, by which
more perfect results than heretofore attained are produced.
The following is a description of the construction as shown in the Drawings,
which may, however, be modified in some of the details and in general con-
figuration, as will be évident to any competent engineer, while in all cases the
main principle of a central surface condenser with lateral branching tubes and
recesses in one or more series is maintained. I form oblong sections of cast
iron or other suitable metal designated in the several Figs. by a, upon which
a series of lateral tubes 6 may be cast, opening into the center section a, or
holes alone may be formed in the section, and the tubes otherwise affixed
thereto by brazing, or screwing, or bolting; these tubes b, which form recesses
on either side, I form in a peculiar manner, by attaching another tube b¹ within
it, the attachment being at the extreme outer end of tube b, as clearly shown
in Fig. 5, by which an anular space is left between the tubes opening into the
center section; a second inner tube 6" may be affixed to the inner end of 6', and
others to any convenient number, being as clearly shown in the Drawing, placed
one within another and attached at opposite ends alternately, so as to form
a series of concentric recesses of any number from one upward to the maxi-
mum point of subdivision, leaving on the outside, on both sides of each of these
recesses, a water space for the outside water of condensation; the several tubes
should be somewhat conical, as in the Fig. 5, and the inner one closed at the
inner end, as there shown at 67. The attacliments of the tubes may be made

page_text: by screws, as in the Drawing, or by any other known and sufficient means;
depending upon the material of which the tubes are made; this may be iron or
other metal, cast or wrought. A series of sections like that just described
may be bolted together by flanches on the upper or lower edges, or otherwise
firmly attached, the joints being packed and joints broken by a projection from
the top of the sections entering the bottom of the one above it.. In the Draw+
ing there are three of these series of sections placed beside each other (more
or less may be used); these may be so arranged as to have their lateral tubes
nearly fill the interior of the outer case c that surrounds them.. This sur-
rounding case may be made of thin metal, and contains the water used for
condensing. The sections thus described rest upon a plate e at the bottom, which
covers another chamber f below, in which are a series of coils of pipe g, one
coil for each section; these coils of pipe 9 pass through the plate e and con-
nect with the bottom of the section a, and thence coiling spirally around, as in
the Fig. 4, communicates with the. pump well, thus uniting the pumps with
the interior of the sections; the chamber is freely supplied with cold water
from the outside, the cold water also surrounding the pump well and valves.
Instead of the large and powerful air pump usual, I prefer to use two small
pumps, which I find sufficient for the purpose; these pumps draw the con-
densed water from the coils and force it into the case c surrounding the
sections, which is filled with water, and from whence the water passes to the
boiler. This water surrounding the sections I keep at a very bigh degree of
heat, up to nearly the boiling point at the top, and produce a constantly
ascending column by the injection from the pumps, and the large. globules of
heated water produced by the current from the pumps and from the surface
of the condenser, which is more active in consequence of the surface water
being heated. It may be here proper to remark that I have by careful ex-
periment found that warm water extracts the heat from steam more rapidly than
cold water does, as I apprehend, for the following reasons:-Water is a bad
conductor of heat when in a quiescent state, and unless. the globules of
vapourized water are at once made large enough to exert an active force to
pass off in ascending currents, they absolutely retard the condensation; after
the condensation takes place, however, a diferent state of things exists, then
the condensed vapour is to be cooled down by itself, passing over cooled sur-
faces such as the coil, which on an inspection of my apparatus it will be seen
is provided therefor, besides which, by the gradual extraction of the heat from
top to bottom of my apparatus, less expansion and contraction of the metal of
the condenser takes place at each inspiration of steam. The water in the
upper section of the case c is hot, the condensed steam passing through the

page_text: pumps into an air chamber 1, where the air and permanent gases are sepe-
rated and occasionally let off through the stop-cock ; or instead of this
chamber being at this point it may be at m, at the top of the condenser caso
c; whence the heated water passes through pipe n to the boiler; thus it will
be seen that nothing but pure water ever comes in contact with the heated
surface of the condenser tubes, either outside or inside, and pure water alone
is supplied to the boiler. The steam from the engine passes into the interior
of the sections of the condenser through the induction or steam pipe p; just
before it enters the condenser it enters a receptacle under an evaporator i that
is employed to supply the waste occasioned by leakage, &c. of the boiler
and machinery; this receptacle is formed of short upright tubes, as seen
in Figs. 2, 3. The evaporator is filled from the outside with water from any
source, impure or otherwise, through pipes k; a pipe r leads from the top of
the evaporator down into the steam induction pipe i, and all the vapour gene-
rated in the evaporator is conveyed by it into the condenser with the steam
from the engine, and adds to the supply and makes up for the deficiency made
by leakage, as before named. The contents of the evaporator can be occa-
sionally blown off when it gets foul through pipe o.
Having thus described my condenser for surface condensation, and the
evaporator connected therewith, what I claim therein as new and for which I
desire Letters Patent is, the central section having lateral chambers or tubes
'connected 'therewith, substantially in the manner and for the purposes set
forth.
I also claim passing the water of condensation into the medium surrounding
the section in the case or surfaces of condensation on its way to the boiler, as
and for the purposes described.
I also claim the coiled tube or its equivalent for conveying the condensed
water to the pumps, as specified.
I also claim the combination of the evaporator herein described, with the
condensér, as described.
JAMES M. MILLER. (L.S.)