IMPROVEMENTS IN FEED WATER HEATERS OR APPARATUS FOR STEAM BOILERS
Year: 1878

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
FEED WATER HEATERS OR APPARATUS FOR STEAM BOILERS." A communi-
cation from abroad by Henry Buick, temporarily residing at Rotterdam, in
the Kingdom of Holland.
;
led the 4th April 1879, and dated the 29th October 1878.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at the
Office of the Commissioners of Patents on the 29th October 1878.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN FEED WATER HEATERS OR APPARATUS FOR
STEAM BOILERS." A communication from abroad by Henry Buik, temporarily
residing at Rotterdam, in the Kingdom of Holland.
This Invention relates to an arrangement of feed water heater whereby the
water which is extracted from the surface condenser of an engine by the air pumps
and falls into the hot well is conveyed back and introduced at the root of the
exhaust pipe in an opposite direction to the exhaust steam as it passes through the
pipe from the cylinder to the condenser to be condensed; the water thus receives
heat from the steam and all hot surfaces with which it comes in contact and falls
on to a metal plate provided for its reception at the root of the exhaust pipe over
the tubes, the said plate being so formed as to conduct the water off the tubes away
by the hottest path to the air pumps to be returned to the hot well, and in part
returned again through the pipe.
The apparatus consists of a pipe leading from the bottom of the hot well to the
root of the exhaust pipe, at which place a stop valve is provided which opens or
closes the communication as required; from the stop valve the pipe continues
through the exhaust pipe, and is elbowed to point in an opposite direction to the
stean passage. Under the exhaust pipe, and of sufficient area to catch or intercept
all, the heater coming from the pipe is a plate of metal which is so formed as to
project the water off the tubes of the condenser away to its sides or hottest parts,

page_text: by which it is conducted to the bottom of the condenser or nearest way to the air
pumps, where it is returned-to-the-hot-well. The-end-of-the-feed_suction pipe is
raised to retain a quantity of water constantly at that part independent of the
water which the pipe conveys away; the pipe conducting the water to the exhaust
pipe is also arranged as low down as possible in order to insure the water being
retained there.
The apparatus operates in the following manner :- -When the engine is in motion
on opening the stop valve the water enters to supply the place of the vacuum, and
by the force it receives passes along through the pipe into the exhaust pipe and
continues-its-course-up-the-pipe-to-the-top, where_by_its_impingement it is divided
into spray and takes up heat from the steam and hot surfaces in so doing, after
which it falls and runs down on to the plate where it is conducted away to the
bottom and into the air pumps to be returned to the hot well again, and again to
be brought back to take up more heat, and so on in succession.
The pipe inside the exhaust pipe is in some cases provided at its end with a rose
for the purpose of dividing the water into spray, the rose being equal to the area
of the pipe, that is to say, the number of small holes being sufficient for the area of
the pipe.
The apron plate is suspended in such a manner as to catch or intercept all the
water, and preserve it from contact with all cold surfaces as it passes to the air
pumps.
It is not essential that the water should descend to the bottom of the condenser,
as it may be otherwise.conducted to the air pumps.

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 21st
April 1879.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN FEED WATER HEATERS OR APPARATUS FOR
STEAM BOILERS." A communication from abroad by Henry Buik, temporarily
residing at Rotterdam, in the Kingdom of Holland.
The said Invention relating to feed water heaters or apparatus for steam boilers
consists in the combination, substantially in the manner herein-after described,
with the hot well air pump or pumps and condenser of a condensing steam engine
and their appurtenances of a system of pipes whereby the water or a portion
thereof, which is drawn from the condenser by the air pump or pumps and directed
into the hot well is conducted to the exhaust pipe and again returned to the hot
well for the purpose of extracting the whole of the heat available in the exhaust
steam and contact surfaces for heating the feed water.
The accompanying Drawing represents a sectional elevation of so much of a
steam engine as is sufficient to illustrate the. said Invention with the same applied
thereto.
A is the hot well; B is the air pump; C is the surface condenser; D is the
cylinder of the engine, a, a, being. its steam induction ports and b its exhaust port,
and E is the exhaust pipe leading from the cylinder D to the surface condenser C,
all of which may be of any usual or suitable description. In the ordinary operation
of condensing steam engines the steam discharged from the exhaust port b passes
through the exhaust pipe E to the condenser C where it becomes condensed, the
water of condensation is then drawn by the air pump B from the condenser C
through the foot valve c, and passing through the air pump, bucket d, and delivery
valve e, is discharged into the hot well A, whence the water for supplying the
boiler is drawn by force pumps or otherwise through the pipe fas is well
understood.
According to the said Invention a pipe F is employed leading from the bottom
of the hot well A at g, passing into and through the exhaust pipe E and debouching
at g', (where it is turned downwards) into another and larger pipe G which leads
from the mouth of the exhaust port b at h (in close proximity to the slide valve) to
the lower part i of the air pump beneath the bucket d. A portion therefore of the
water of condensation which is conducted into the hot well A is by the pressure of
the atmosphere acting upon the surface of the water in the hot well against the
vacuum caused by condensation and by the operation of the air pump forced from
the hot well A along the pipe F into the pipe G at g¹, at this part the water meets
that portion of the escaping exhaust steam which may have entered the pipe G at h
and effects the condensation of such steam, acquiring heat therefrom, the water
thus partially heated is then drawn down the pipe G under the action of the air
pump B, which it enters at i, thence passing through the bucket d and delivery
valve e into the hot well A to be again in part conveyed back by the pipe F and
returned, having taken up fresh heat by the pipe G to the hot well, and so on in
succession, maintaining a constant circulation through the apparatus.
The pipe F is provided with a stop-cock k for shutting off or regulating the
circulation, and the pipe G is also fitted with a stop check valve at opening
upwards, which may be closed or adjusted as required. The pipe G may be further
provided with baffles (in the form of wires) in its interior in order to retard the
passage of the water and cause it to take up more readily the whole of the available
heat from the exhaust steam passing through the pipe. It is preferred to continue
the inner end of the pipe f upwards within the hot well A, as shewn at f', in order.
to ensure that a sufficient quantity of water is constantly retained within the hot
well. It is found advisable in practice to arrange the orifice at fin relation to the

page_text: boiler feed pump when a feed pump is employed, so that the said orifice will be
at the same height as or above-the-level-of-the-valves-of-the-boiler_and_pump._
By means of the said Invention nearly the whole of the waste heat is rendered
readily available in heating the feed water by the use of apparatus simple and
economical in construction and not liable to be put out of order.
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,-
The combination with the hot well air pump or pumps and condenser of a con-
densing steam engine and their appurtenances, of a system of pipes whereby the
water or a portion thereof, which is drawn from the condenser by the air pump or
pumps and directed into the hot well is conducted into the exhaust pipe and again
returned to the hot well, for the purpose of extracting the whole of the heat
available in the exhaust steam and contact surfaces for heating the feed water,
substantially as herein-before described.
In witness whereof, I, the said John Henry Johnson, have to this my Specifica-
tion set my hand and seal, the Eighteenth day of April, One thousand
J. HENRY JOHNSON. (L.S.)