IMPROVED FEED WATER HEATING APPARATUS FOR STEAM BOILERS
Year: 1873

page_text: PROVISIONAL SPECIFICATION left by Alexander Melville Clark at
the Office of the Commissioners of Patents, with his Petition, on
the 24th June 1873.-A communication from abroad by Hector
de Bardel, of Paris, France.
I, ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the
County of Middlesex, Patent Agent, do hereby declare the nature of
the said Invention for "IMPROVED FEED WATER HEATING APPARATUS FOR
STEAM BOILERS," to be as follows:-
-
This Invention relates to improvements in tubular feed water heaters
applicable to all kinds of steam boilers, the arrangement being slightly
varied to suit the kind of boiler to which the heater is to be applied.
One arrangement or rectangular form for use with fixed and marine
engine boilers is illustrated in Figures 1, 2, 3, and 4 of the annexed
Drawings.
In the case of marine boilers the feed water heater should be placed as
near to the condenser as possible and behind the same so as to be near
the tanks and pumps.

page_text: In fixed horizontal or beam engines the feed water heater may be
placed in the engine room or near the boiler, the only difference in the
two arrangements being in the temperature of the feed water.
I will proceed to describe the improvements as applied to a marine
engine of mean pressure provided with a surface or other condenser.
The rectangular tubular heater is composed of a cast-iron bed A, B,
C, D, E, F, Figure 4, made in two parts bolted together, on the smaller
of which are bolted three rectangular chambers A, B, C, termed small
heaters. Their covers are made removable and their bottoms are each
provided with a man-hole to facilitate the cleaning of the outsides of
the clusters of tubes by which cach heater is traversed. These tubes
are arranged closely together in rows crossing one another as shown, and
thus present a large amount of heating surface, and subdivide the volume
of water and retard it in its passage from the tanks through the heaters,
and so afford time for the absorption of caloric.
For the purpose of further retarding the flow and thus of increasing
the absorption of caloric by the water the top of cach of said heaters is
made to communicate with a cylinder D, D¹, D", each traversed by a
number of small tubes. The lower part of each cylinder D com-
municates with the bottom of the next heater and so on, as shown in
Figure 3. The cylinder casings have vertical slits or apertures through
which the steam enters and surrounds the tubes. The cylinder D" is in
direct communication with the large heater herein-after described. The
said three small cylinders and the small heaters comprise the first part
of the apparatus in which the temperature of the water from the tanks
first begins to rise.
The subdivision of the water by passing it first through small heaters
as described is designed to prevent the temperature of the whole being
lowered by the direct introduction of a liquid at a low temperature into
that of a higher temperature contained in the large heater..
The large heater E annexed to the smaller heaters above described is
of precisely similar thereto construction. It is formed of four lateral
tube plates to which the top and bottom covers are fitted. The lower
cover rests on the bed and is provided with a man-hole and two apertures
through which the pipe F communicates with the small heaters, and an
additional supply pipe G to be used if by accident there should not be
sufficient fresh water in the tanks to fill the apparatus. The top cover

page_text: carries a pipe on which is fixed what I term an expansion valve H with
escape pipe I leading to the tanks and also a small gauge and feed
pipe J.
The tubes in the large heater are of the same diameter and arranged
in the same manner as in the small heaters before described. Both
heaters are enclosed in a casing K, K', fixed to the bed A, B, C, and
composed of sheet iron covered with felt encased in wood and divisible
into two parts like the bed plate.
The steam is introduced into the apparatus from the boiler by a
pipe L encased with felt and wood, by which means nearly the whole
heat of the steam is retained and it enters the apparatus at nearly the
same temperature as when it left the boiler.
Before its introduction into the heater it is caused to pass into a small
apparatus termed a purifier in which it is deprived of the fatty and oily
matters held in suspension. This purifier consists of a rectangular or
cylindrical casing M, the upper part of which communicates by means
of a valve. M¹ with the steam supply pipe L from which a branch
provided with a valve N connects with the casing of the heater.
The purifier contains three discs of wire cloth a, b, c, mounted on a
central rod fixed to the bottom cover. The lower part of the purifier
pipe with valve O³. The parts
also communicates with the casing by a
being thus arranged valve N on the upper branch pipe is closed and the
two other valves M¹, O2, above and below the purifier are opened. The
steam then passes through the wire gauze and enters the apperatus by
the lower valve, any extraneous matters being deposited on the gauze.
If after 4 or 5 days the gauze should become clogged the two valves M',
O, are both closed so as to isolate the purifier, the steam continuing to
pass into the apparatus through the upper branch pipe and valve N.
In a few minutes the bottom cover is removed, the clean wire clothi
replaced, and the lower valves are then opened and that of branch N
closed. By this means the cluster of tubes require cleaning only at
long intervals; P, p', purge cocks to remove the water of condensation.
To avoid this condensation the liquid may be returned to the boiler by a
return tube P opening into the lower part of the steam chest in order
that a circulation may be produced by the difference in tension of the
two gazcous bodies, the other tube being connected to the top of the
steam casing.

page_text: The action of the apparatus is briefly as follows:-Water is admitted
by opening valve Q until the water rising in the small heater circulates
through the cylinders and fills the large heater. The valves of the
purifier are then opened to admit steam which surrounds the heaters
and circulates through their tubes, whereby the water is heated and
expands, the overflow passing out through the expansion valve back to
the tanks. The valves are so regulated that the apparatus is kept
supplied with water as fast as it is drawn off to feed the boiler, so that
the apparatus being kept completely filled the water may even be
heated above boiling point without being vaporised until its entry into
the boiler where it is then immediately converted into steam.
It is to be observed that the boiler being constantly in communication
with the heater the latter does not detrimently absorb heat as the
boiler heats its own feed water. At first the steam pressure is lowered
but as soon as the transmission of heat ceases the steam only serves to
maintain the heat and the pressure again rises. .
Figures 5 and 6 show the cylindrical arrangement which, except in
form, differs but slightly from that above described, and is precisely
similar thereto in its action; A, large cylindrical heater mounted
on a bed constructed as shown, the heater being filled with tubes 2
and provided with an expansion valve B, pipe C, and valve D;.
E, F, man-holes.
Around the large heater are disposed a number of small heaters also
cylindrical and tubular as shown. The water from the tanks enters by
tube G in the first small heater a, in which it rises to the top and is then 2
conducted through a pipe to the bottom of the next small heater b, and
so on throughout the series c, d, e, f, g, h, i, j, k, until it reaches 1,
whence it passes by tube H, H, into A. The whole is enclosed in a
steam casing K, L, as before, and the steam from the boiler passes first
through a purifier I, as above described and entering casing K, L, 3
circulates around and through the heaters and returns (if there be a
circuit) to the boiler by tube J; f,f¹, purge cocks placed beneath the
bed plate; M, small opening to empty the heater A for cleaning.
Figures 7 and 8 show the feed water heater as applied to a locomotive..
In this case the heater is composed of a casing A, B, C, D, bolted 3
to the inside of the smoke box.. The casing is provided with compart- .
ments E, E¹, termed steam chambers, one on either side. The. centre.

page_text: casing forms the heater and is traversed from back to front by tubes
corresponding to and forming a continuation of the boiler tubes as shown
at a, b, c, d, e, Figure 8. The intervening spaces are filled by
transverse tubes through which the steam from the boiler is conducted
by a pipe F from steam dome G, the supply being regulated by cock N
operated by a rod H. The blast pipe I passes up the centre of the
apparatus to impart its heat thereto. The top cover of the heater
carries an expansion valve box J with overflow pipe K. A pipe L of
small diameter passes along the back of the engine within view of the
driver and is provided with a thermometer and gauge. The steam pipes
may also be made to pass through the steam chambers as shown in
Figures 7 and 8, which dries the steam. The heating of the water in
the heater is effected both by the products of combustion passing in a
longitudinal direction and also laterally by the steam from the boiler,
and vertically by the blast pipe.
Water is supplied to the apparatus by a pump placed on the right-
hand side of the engine which supplies cold water from the tender to an
apparatus for controlling the rate of supply, shown in Figure 9,
consisting of compartments A, B, C₁, forming small steam chambers
supplied by a pipe O and other compartments D', E¹, F¹, forming
tubular water heaters connected by pipes G', H³, I. The latter
pipe I connects with the bottom part of the heater I', Figure 7. A
similar controlling apparatus connects with a second pump for supplying
the heated water to the boiler by means of valve J and pipe P, the feed
being regulated by cock R; S, T, man-holes to afford access for cleaning
out the lateral steam tubes; to facilitate the removal of the whole
apparatus for cleaning the steam pipes need not pass through the steam
chambers E, E¹, or the steam pipes may be jointed together in lengths
with a similar object.