Improvements in Apparatus for Condensing Steam.
Year: 1896

page_text: Date of Application, 12th Nov., 1896
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Condensing Steam.
We, JOHN ISAAC THORNYCROFT, F.R.S. of Chiswick Mall, Chiswick, in the
County of Middlesex, and THE STEAM CARRIAGE & WAGGON COMPANY LIMITED,
of Chiswick, aforesaid, Auto-car Builders, do hereby declare the nature of this
invention to be as follows:-
This invention has reference to a construction of surface condensers wherein
steam can be readily condensed by the action of air coming in contact with steam
containing portions of the apparatus thereby rendering it suitable for use in
steam propelled vehicles such as tramway locomotives and motor cars running
on common roads. Such a condenser we make with thin tubes of metal that is
a good conductor of heat, which tubes are constructed or provided with a series
of thin fins or gills that project outward laterally to a distance that is consider-
able in comparison with the diameter of tube, these lateral projections being
so arranged that between them spaces are left for the passage of air which
impinging upon the exposed surfaces will take up heat from the steam that is
in the tubes and so will cause rapid condensation. According to one mode of
carrying out the invention each tube is made or provided with one or more
extremely thin flanges wide as compared with the diameter of the tube and
running the entire length of the tube, these flanges being cut transversely at
short intervals into a number of narrow parts each of which is at its inner end
integral with or joined to the tube, and is twisted in such a manner that there
are formed a series of lateral projections with spaces between them that will
allow currents of air to pass, and will present efficient surfaces for the air to act
against.
We have found that tubes with small fins or gills such as above described
give a much better result than an equal extent of surface not so sub-divided.
It will be understood that the surface of each lateral projection constitutes a
small area which by reason of the arrangement we adopt is traversed by air
that has not just previously been flowing over another portion of surface belong-
ing to the same tube.
A convenient
Condensers according to this invention can be constructed so that the flow of
air may be that due to the passage through the air of vehicles carrying such
condensers or the flow of air may be caused by special apparatus such as fans
blowers or exhausters or by a combination of such means. Also in our improved
condensers we sometimes make special provision for readily and automatically
removing the water of condensation as the steam is condensed.
arrangement of condenser comprises a number of transversely arranged tubes
having fins or gills, these tubes being connected at their ends in series by longi-
tudinal tubes provided with diaphragms to cause the steam to flow from one
longitudinal tube through one series of transverse tubes to the other longitudinal
tube, and thence back again by another series of transverse tubes and so on;
small holes being formed through the diaphragms to enable the water of con-

page_text: densation to flow along the longitudinal tubes to suitable points whence it can
be conveyed to the feed or water tank.
Dated this 12th day of November 1896.
COMPLETE SPECIFICATION.
Improvements in Apparatus for Condensing Steam.
We, JOHN ISAAC THORNYCROFT, F.R.S. of Chiswick Mall, Chiswick, in the
County of Middlesex, and TuE STEAM CARRIAGE & WAGGON COMPANY LIMITED,
of Chiswick, aforesaid, Auto-car Builders, do hereby declare the nature of this
invention and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement:--
This invention has reference to a construction of surface condensers wherein
steam can be readily condensed by the action of air coming in contact with steam
containing portions of the apparatus thereby rendering it suitable for use in
steam propelled vehicles such as tramway locomotives and motor cars running
on common roads. Such a condenser we make with thin tubes of metal that is
a good conductor of heat, which tubes are constructed or provided with a series
of thin fins or gills that project outward laterally to distance that is consider-
able in comparison with the diameter of tube, these lateral projections being
so arranged that between them spaces are left for the passage of air which
impinging upon the exposed surfaces will take up heat from the steam that is
in the tubes and so will cause rapid condensation.
Referring to the accompanying illustrative drawings
Fig. 1 is side view of a portion of an air condenser tube according to this
invention; and
Fig. 2 is a transverse section thereof.
The tube A is made or provided with one or more extremely thin flanges B
wide as compared with the diameter of the tube and running the entire length
of the tube, these flanges being cut transversely, at short intervals into a number
of narrow parts B¹ each of which is at its inner end integral with the tube, and
is twisted, as shown at the upper part of Fig. 1, in such a manner that there
are formed a series of lateral projections with spaces between them that will
allow currents of air to pass, and will present efficient surfaces for the air to act
against.
The tube A is formed in one with its fins B', from a thin sheet of copper bent
to a tubular form with a flange projecting tangentially on each side of the tube
seam which is soldered, as shown at B2 in Fig. 2.
Fig. 3 illustrates a modified construction in which the fins are made separate
from the tube and the two parts are joined by solder as indicated at 133.
Fig. 4 illustrates a further modification in which the tube A and fins are
made in one piece, the tube being made complete without soldering and the fins
being arranged to extend diametrically therefrom and preferably tapered towards
their outer edges.
We have found that tubes with small fins or gills such as above described give
a much better result than an equal extent of surface not so sub-divided. It
will be understood that the surface of each lateral projection constitutes a small
area which by reason of the arrangement we adopt is traversed by air that has

page_text: not just previously been flowing over another portion of surface belonging to
the same tube.
Fig. 5 is a side view of a portion of a set of condenser tubes provided with
fins according to this invention; the tubes A are soldered to one side of a thin
metal plate as shown and the fins of the several tubes in the set are formed by
making a series of short parallel slits in those parts of the plate that lie on each
side of and between the tubes A and twisting or bending the strips of metal thus
formed to the required angle.
Fig. 6 shows in horizontal section two sets of tubes such as shown in Fig. 5.
The tubes might be joined some to one side and some to the other side of the
plate, if desired.
Condensers according to this invention can be constructed so that the flow of
air may be that due to the passage through, the air of vehicles carrying such
condensers, or the flow of air may be caused by special apparatus such as fans,
blowers or exhausters, or by a combination of such means. Also in our improved
condensers we sometimes make special provision for readily and automatically
removing the water of condensation as the steam is condensed.
A convenient arrangement of condenser comprises a number of transversely
arranged tubes having fins or gills, these tubes being connected at their ends
in series by longitudinal tubes provided with diaphragms to cause the steam to
flow from one longitudinal tube through one series of transverse tubes to the
other longitudinal tube, and thence back again by another series of transverse
tubes and so on; small holes being formed through the diaphragms to enable
the water of condensation to flow along the longitudinal tubes to suitable points
whence it can be conveyed to the feed or water tank.
Fig. 7 is a plan of such an arrangement of condenser; Fig. 8 is a section on
the line a- Fig. 7; and
Figs. 9, 10, 11, 12, 13, 14, 15 and 16 are detail views drawn to a larger scale
and hereinafter referred to.
A, A are the tubes having fins or gills arranged edge on to the air through
which they travel as above described, but for the sake of clearness the fins or
gills are not shown. The tubes are arranged in two rows and are connected at
their ends to longitudinal tubes C. The condenser is built up in sections, each
section comprising two short lengths of tube C connected by ten tubes A which
are preferably bent as shown in Fig. 9 and the ends of which are expanded into
the tubes C. The outer ends of the outermost lengths of tube on, one side of the
condenser are closed hy cap pieces C (see Figs. 9 and 10) whilst those on
the other side are fitted with inlet and outlet pipe couplings or connections C3
(see Figs. 11 and 11). The various lengths of tube Cat each side of the cou-
denser have, as shown in Fig. 12 interposed between them diaphragms D (Figs. 13
and 14) and couplings rings E (Fig. 15); the several sections are clamped together
by pairs of long bolts or rods F, which pass through holes D in the projecting
parts of the diaphragms D (Figs. 12 and 14) and in the cap pieces C and con-
nections C, and nuts F. The diaphragms 1) are formed with small drain
holes D. In Fig. 12 a set of four sections are shown thus clamped together,
one pair of rods F being used. The central diaphragm D is of the kind shown
in Fig. 13, and is held in position by the rods which enter recesses in lateral
extensions thereof. G, G (see Figs. 7 and 16) are coupling rings, formed with
projecting portions that have perforations G to receive the ends of the rods F.
The other sections are coupled together in the same manner, the rods Falso
serving to couple adjacent sets of sections together; for this purpose the rods
of each pair pass through the holes D¹ G' that are diametrically opposite each
other.
Between each two sets of sections clamped together in the manner described
there is interposed a single section C, it and the adjacent sets of sections being
clamped together by a pair of short bolts such as F, which pass through the holes

page_text: in the diaphragms D) or connecting rings G not occupied by the pairs of bolts F
that serve to hold together the sections of the adjacent sets.
It will be seen from Fig. 7 that the arrangement of diaphragms D and coupling
rings E and G, is such that steam admitted to the condenser at H is caused to
flow in a zig-zag fashion through the tubes A of all the sections successively,
the water of condensation, which passes through the holes D2 in the diaphragms,
escaping at I.
Figs. 17 and 18 are respectively a plan and a rear elevation of a modified
construction of condenser in which the tubes C that connect in series the trans-
versely arranged tubes A having fins or gills are vertical, the lower ends of each
tube C being provided with a funnel shaped diaphragm D, the outlet portion of
which is let into a pipe J adapted to lead off the water of condensation that
passes through the diaphragms. The tubes C on each side of the con-
denser are connected in pairs at their upper ends by junction pieces K as
illustrated in Figs. 19, 20 and 21 which are detail views to an enlarged scale.
The junction pieces are secured by rods L that screw at their lower ends into
sleeves M embracing the pipes J and at their upper are fitted with tightening
nuts as shown. It will be seen from Fig. 17 that the arrangement is such that
steam admitted at H will be caused to flow in a zig-zag fashion through all the
sets of transverse tubes A as in the previously described arrangement.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed we declare that what
we claim is:-
1. An apparatus for condensing steam made with thin tubes of metal that is a
good conductor of heat, which tubes are constructed or provided with a series
of thin fins or gills that project outward laterally to a distance that is consider-
able in comparison with the diameter of tube, these lateral projections being so
arranged that between them spaces are left for the passage of air which, impinging
upon the exposed surfaces, will take up heat from the steam that is in the tubes
and so will cause rapid condensation substantially as hereinbefore described.
2. The manufacture from thin sheet metal as hereinbefore described of
apparatus such as referred to in the preceding claim for condensing steam.
3. The several constructions of surface condenser tubes having a series of thin
and narrow fins or gills hereinbefore respectively shown in and described with
reference to Figs. 1 and 2, Fig. 3, Fig. 4 and Figs. 5 and 6 and Fig. 7 of the
accompanying drawings.
4. A surface condenser comprising a number of transversely arranged tubes
having fins or gills connected at their ends in series by relatively longitudinal
tubes provided with diaphragms to cause the steam to flow from one longitudinal
tube through one series of transverse tubes to the other longitudinal tube, and
thence back again by another series of transverse tubes and so on substantially
as described with reference to Figs. 8 to 16 inclusive and to Figs. 17 to 21
inclusive of the accompanying drawings.
Dated this 12th day of August 1897.
For the Applicants,
W. LLOYD WISE,
46 Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.