Improvements in Feed-water Heaters for Steam Generators.
Year: 1894

page_text: COMPLETE SPECIFICATION.
Improvements in Feed-water Heaters for Steam Generators.
I, SAMUEL HEY of 56 Low Street, Keighley, in the County of York, Patent
Agent, do hereby declare the nature of this invention, as communicated to me from
abroad by John Otis Davis of Hartford in the County of Hartford and State of
Connecticut, United States of America, Gentleman, and in what manner the same
is to be performed, to be particularly described and ascertained in and by the
following statement:-
This invention relates to that class of steam-generator feed-water heaters
employing return-tubes for circulating exhaust-steam in a casing through which the
feed-water passes, with the object of extracting the heat of the exhaust-steam and
utilizing it to heat the feed-water. The object of the invention is to more thoroughly
accomplish this result by providing large areas of heat-radiating surface and
insuring a more extended distribution of the exhaust-steam than heretofore, due
regard being had at the same time for compactness.
To the above ends, the invention consists in certain novel features of construction
and combinations of parts hereinafter described and claimed.
The accompanying drawing illustrates a construction embodying the invention.
Figure 1 shows a longitudinal section of the heater.
Figure 2 shows a cross-section on line 2-2 of Figure 1, broken lines indicating
the return bends of the pipes.
Fig. 3 shows a cross-section on line 3-3, Figure 1.
The letter a designates a cylindrical casing closed at both ends and having an
inlet opening a¹ in the under side near one end for the entrance of the feed-water,
and an outlet opening a² in the upper side near the opposite end for the discharge
of the feed-water. Perforated baffle-plates & extend over the openings a¹ and a²
respectively, and throughout the length of the shell to which they are riveted.
These baffle-plates may, however, be dispensed with.
A casting c is secured on one head a³ of the shell a, and is formed with a series
of horizontal chambers e¹ in its inner side and having their front sides closed by the
head a³. The upper one of the said chambers has an opening for admission of
exhaust-steam or condensation from an engine, and the lower chamber has an opening
for the discharge of this exhaust-steam or the condensation thereof. A system of
return-tubes connects the chambers and extends throughout substantially the whole
length of the shell, the arrangement being as follows; each return-tube comprises
two parallel lengths d entered at the forward end through the head a³ and connected
at the opposite end by a return bend d'. One length of tube communicates with
one chamber c¹, and the other with the adjacent chamber. The tubes are arranged
in horizontal tiers, and those composing the upper tier connect the upper chamber
with the next chamber below, and those at one side of a central vertical line of the
shell are disposed at varying degrees of inclination in one direction, the degree of
inclination increasing toward the said central line, whereas those on the other side
of said central line are disposed at correspondingly varying degrees of inclination
in the opposite direction (see Figure 2). The tubes of the next tier connecting
the second and third chambers are lengthwise disposed, those at one side being
inclined in one direction and those on the other side in the opposite direction; and
the tubes composing this second tier are staggered with respect to the tubes
composing the first tier, so as to throw the ends of the tubes of different tiers which
issue in the same chamber out of vertical alignment.
The third tier of tubes connecting the third and fourth chambers are disposed
vertically and staggered with respect to the tubes of the second tier to secure the

page_text: same relative position of the ends of the tubes as above described. Two other tiers
of tubes on the lower sides of the central tier and connecting the fourth and fifth,
and the fifth and sixth chambers, are arranged the same as the two above the
central one.
In operation, the exhaust-steam or condensation entering the upper chamber
passes through the tubes composing the upper tier, and is delivered thereby into
the chamber next below, whence it passes into the tubes of the second tier as
indicated by the arrows in Figure 2, and is conducted thereby to the chamber next
below, and so on to the bottom chamber.
The heat of the exhaust-steam is extracted by the feed-water, and the resultant
condensation is discharged from the lower chamber c, together with oils and other
foreign matter which accompany the exhaust-steam.
It is to be noted that there is no admixture of the exhaust-steam and the feed-
water.
By my staggered arrangement of the return-tubes, I secure a more thorough
distribution of the exhaust-steam than if the tubes were in vertical alignment, for
with the staggered arrangement the discharging ends of one tier of tubes enters the
chamber out of vertical alignment with the receiving ends of another tier of tubes
and causes an extended distribution of the exhaust-steam throughout the chamber.
The angular disposition of the tubes herein before described adapts them to a
prescribed compass in which to include them, and secures large areas of
heat-radiating surface.
h
The pipes are sustained at the back of the shell by a support in the form of a
perforated plate through which the pipes extend, and which is bolted through
suitable lugs to the shell.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is ;-
A feed-water heater comprising in its construction an exterior casing, a head on
one end of said casing having a number of horizontal partitions forming separated
chambers, and tiers of return-tubes extending longitudinally within the casing, each
tier connecting adjacent chambers in the said head, and said tiers comprising outer
tiers the return-tubes of which at one side of a central vertical line are inclined in
one direction in varying degree, while those at the other side of said line are
correspondingly inclined in the opposite direction, intermediate tiers whose tubes
are inclined substantially as those of the outer tiers and staggered with respect
thereto, and a central tier whose tubes are staggered with respect to those of the
intermediate tiers, all substantially as described.
Dated this 17th day of September 1894.