Evaporating by Means of Steam.
Year: 1887

page_text: Date of Application, 25th Apr., 1887
Complete Left, 23rd Jan., 1888
Complete Accepted, 24th Feb., 1888
or Evaporating by Means of Steam..
WC, JAMES WEIR, and GEORGE WEIR, both of 2 Commerce Street, Glasgow, in the
County of Lanark, North Britain, Engineers, do hereby declare the nature of this
Invention to be as follows, that is to say:
Our said Invention has for its object to increase the efficiency of apparatus for
condensing steam or for heating or evaporating by means of steain, the apparatus to
which our improvements are applicable being of the kind in which the steam passes
through a number of tubes.
a
In general, the steam passed into apparatus of the kind to which our Invention
relates, has air associated with it, and if currents are not continuously maintained
through all the tubes, the air accumulates and lodges in any tube in which there is
little or no current, and renders such tube practically inefficient as a heat exchanging
medium. The steam, whether it is being condensed for the purpose of forming
vacuum as in a steam-engine condenser, or is being used for heating or evaporating
water or other liquid, becomes reduced in volume as it passes along the tubes; and
as the tubes are ordinarily of oqual area at both ends the discharge of water of
condensation or of a mixture of such water with vapor and air is necessarily com-
paratively slow. And it happens in practice that in certain circumstances little or no
discharge takes place through some of a set of tubes whilst steam may blow quite
through others, which leads to air being accumulated in the tubes through which there
is little or no current.
In carrying out our Invention in the case of a steam-engine condenser in which
there are a comparatively large number of tubes, we partition off the spaces with
which the ends of the tubes communicate so as to divide the tubes into sets of
graduated numbers, arranged so that the steam first passes through the set having the
fargest number and then successively through sets having smaller numbers in order.
With this arrangement currents will be continuously maintained throughout all the
tubes and they will all act efficiently.

page_text: In apparatus for heating or evaporating by means of steam in which the tubes are
generally comparatively large and fow in number, the steam is first led through a
large proportion, 90 per centum for example, of the tubes, and is subsequently led
through the remainder. This arrangenient prevents any accumulation of steam or
air at the discharge ends of the larger portion of the tubes and thereby insures
continuous flow through all of them. In many cases especially when the tubes are
few in number the desired object may be attained by fixing rings or perforated plugs
in the discharge ends of the tubes so as to diminish the area at the discharge ends.
Or the modification last described may be combined with the previously described
arrangement in which what passes through the larger proportion of the tubes is again
passed through one or more tubes in which it is subjected to condensing action so as
to insure diminished pressure in the space into which the larger proportion of the
tubes discharge.
Dated this Twants thing dow of Anail 1007
EDMUND HUNT,
Applicants' Agent.
or Evaporating by Means of Steam.
We, JAMES WEIR, and GEORGE WEIR, both of 2 Commerce Street, Glasgow, in s
the County of Lanark, North Britain, Engineers, 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, that is to say :-
Our said Invention has for its object to increase the efficiency of apparatus for
condensing steam or for heating or evaporating by means of steam, the apparatus to
which our improvements are applicable being of the kind in which the steam pssses
through a number of tubes.
In general the steam passed into apparatus of the kind to which our Invention
relates, has air associated with it, and if currents are, not continuously maintained
through all the tubes, the air accumulates and lodges in any tube in which there is
little or no current, and renders such tube practically inefficient as a heat exchanging
medium. The steam whether it is being condensed for the purpose of forming
vacuum as in a steam-engine condenser, or is being used for heating or evaporating
water or other liquid, becomes reduced in volume as it passes along the tubes; and as
the tubes are ordinarily of equal area at both ends, the discharge of water of
al

page_text: condensation or of a mixture of such water with vapor and air is necessarily
comparatively slow. And it happens in practice that in certain circumstances little
or no discharge takes place through some of a set of tubes whilst steam may blow
quite through others, which leads to air being accumulated in the tubes through
which there is little or no current.
In carrying out our Invention we employ apparatus or arrangements of parts of
apparatus of which examples are delineated on an accompanying sheet of explanatory
drawings. Figure, 1, is a vertical longitudinal section of a steam-engine condenser.
Figures, 2, and 3, are sections as at right angles to each other of part of apparatus
for heating or evaporating by means of steam. Figure, 4, is a vertical section of
apparatus which can he used for condensing steam or for heating or evaporating by
means of steam. Figures, 5, and 6, are a longitudinal section and an end elevation
of a part of apparatus for heating or evaporating by means of steam. In these
drawings the same reference numerals are used to mark the same or like parts
wherever they are repeated.
In the case of a steam-engine condenser, such as is shown in figure, 1, in which
there are a comparatively large number of tubes, 7, 8, 9, we partition off the
spaces, 10, 11, 12, 13, with which the ends of the tubes communicato so as to divido
the tubes into sets of graduated numbers, arranged so that the steam first entering
the space, 10, passes through the set, 7, having the largest number into the space, 11,
at the other end of the casing, and then returns through a smaller number of tubes, 8,
into the space, 12, finally passing through a still smaller number of tubes, 9, to the
outlet space, 13. With this arrangement currents will be continuously maintained
throughout all the tubes and they will all act efficiently.
In apparatus for heating or evaporating by means of steam in which the tubes aro
generally comparatively large and few in number, the steam is first led through a
largo proportion, 90 per centum for example, of the tubes, and is subsequently led
through the remainder. This arrangement provents any accumulation of steam or air
at the discharge ends of the larger portion of the tubes and thereby insures continuous
flow through all of them. In many cases especially when the tubes are few in
number the desired object may be attained by fixing rings or perforated plugs in the
discharge ends of the tubes so as to diminish the area at the discharge ends. Or the
modification last described may be combined with the previously described arrange-
mont in which what passes through the larger portion of the tubes, is again passed
through one or more tubes in which it is subjected to condensing action so as to
insure diminished pressure in the space into which the larger portion of the tubes
discharge. This combination of peculiarities is exemplified in the modifications shown
in figures, 2, to 6, of the drawings.
The apparatus shown in figures, 2, and 3, and which is designed to be fitted into
a casing through which the water or liquid to be heated or evaporated is passed, consists
of a casing, 14, provided with a cover, 15, and interiorly divided into an inlet space, 16,
and a discharge space, 17. Tubes, 18, bended to a U-form have each one end fixed so
as to communicate with the inlet space, 16, and the other end fixed so as to commu-
nicate with the discharge space, 17; and plugs, 19, having small holes through them
are fixed in the discharge ends of the tubes, 18. From the dischargo space, 17, the
water of condensation with any air and vapor passes through a tube, 20, to the
outlet, 21, so as to be again subjected to the cooling or condensing action of the water
or liquid in which the tubes, (18, 20) are immersed in the main casing; and by these
means accumulation of air in the discharge space, 17, is prevented and the pressure
is kept low in that space.
In the modification shown in figure, 4, straight tubes, 7, are represented as fixed
in the tube plates by screw glands, 22, 23, those in the discharge space, 17, being
made with contracted orifices. From the discharge space, 17, the water of condensation
with any air and steam pass through a single tube, 9, (or it might be two or three)
to the outlet, 21..
In the modification shown in figures, 5, and 6, a cluster of seven tubes, 24, 25,
each with one end closed, are fixed by their open ends into a plate, 14, upon which a

page_text: cover, 15, is fitted, this cluster of tubes being intended to be fitted into a casing or
vessel through which the water or liquid to be heated or evaporated is passed. In the
tubes, 24, 25, there are small return tubes, 26, 27, which have their onter ends fixed
in a block, 28. The steam passes from the inlet space, 16, into the open ends of the
larger tubes, 24, and returns through the inner tubes, 26, to the block, 28, finding its
way through small holes in that block into an inner cavity, 17, communicating with
the central larger tube, 25. The water of condensation with any air and steam is in
this tubo subjected to the cooling or condensing action of the water or liquid in which
the tubes, 24, 25, are inmersed and returns through the central inner tube, 27, to tho
outlet, 21.
Having now particularly described and ascertained the nature of our said Inven-
tion and in what manner the same is to be performed, we declare that what we
claim is:
1-In a steam-engine condenser or heat exchanger in which steam is condensed or
used to heat or ovaporate water or other liquid, the arrangement of tubes in sets to be
successively passed through by the steam the number of tubes in each set passed
through later being smaller than that in the set next previously passed through
substantially as and for the purposes hereinbefore described.
2-Contracting the discharge ends of tubes in a-condenser or heat exchanger for
condensing steam passing through the tubes or for heating or evaporating water or
other liquid by means of such steam substantially as and for the purposes hereinbefore
described.
8-In a heat exchanger with tubes through which steam is passed, contracting the
discharge ends of tubes through which the steam first passes, in combination with
the provision of one or more additional heat exchanging tubes for the water of
condensation with air and steam to pass through to the outlet substantially as and for
the purposes hereinbefore described.
Dated this Twanty first day of Tanum 1000