steam superheaters
Year: 1897

page_text: I, HUGH MCPHAIL, of The Towers, Wakefield, in the County of Yorks, Engineer,
do hereby declare the nature of this invention to be as follows :-
This invention relates to improvements in steam superheaters and has reference
to an arrangement whereby the steam is caused to pass on its way from the boiler
to the engine through a tubular superheater placed at or near the rear end of the
boiler fue or flues in the path of the furnace gases.
The said superheater comprises two steam boxes or chambers one beneath the
boiler at a short distance from the rear end thereof and the other behind the
boiler above the flues. The tubes of the superheater are arranged in parallel rows
or sèries. They extend horizontally for a short distance from the lower steam box
or chamber and then bend upward with a gradual curvature around the lower edge
of the boiler, and pass up vertically to the second box or chamber.
According to one arrangement the steam is collected in a suitable anti-priming
pipe whence it is led through a pipe which passes down through the water space
of the boiler and is connected to the lower box or chamber of the superheater.
The steam then passes through the tubes of the latter to the upper box or chamber,
whence it may either be taken direct to be utilized, or be taken first through one
or more tubes or channels in the internal space of the boiler.
In the case of a two-flued or Lancashire boiler a single superheater may be
arranged of sufficient width to be heated by the gases from both internal flues or a
superheater of similar construction to that above described may be arranged
behind each flue, in such a manner that the steam to be superheated flows first
through one superheater and then through the other. For this purpose the lower
steam boxes or chambers of the superheaters may be connected together, the upper
box or chamber of one superheater receiving the steam direct, from the steam space
of the boiler, the steam passing down through this superheater and then up through
the other one. From the upper box or chamber. of this latter superheater the
steam may be conducted away either direct to be utilized or through a pipe
passing into the boiler, as in the previous arrangement.
Obviously however the arrangement of the steam connections and the means for
leading the steam through the boiler on its way to or from the superheater may
be varied without departing from the nature of the invention.

page_text: 1936
Improvements in Steam Superheaters.
ス
I, HUGH MCPHAIL, of The Towers, Wakefield, in the County of Yorks, Engineer,
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. relates to steam superheaters and has reference to an improved
arrangement whereby the steam is caused to pass, on its way from the boiler to
the engine, through a tubular superheater of special construction placed at the
rear end of the boiler in the external flue.
The said superheater-comprises-steam boxes or chambers connected by tubes
which near the lower edge of the boiler, bend with a gradual curvature and then
pass upward in a.vertical or approximately vertical: direction:
In order that my invention may be more readily understood I will proceed to
describe the same, with reference to the accompanying drawings, in which
Figure 1 is a side elevation of the rear part of a steam boiler, having, combined
therewith one arrangement of superheater according to my invention.
Figure 2 is an end elevation thereof, and.
Figure 3 is a plan of the same.
Figure 4 is a side elevation illustrating a modified arrangement of superheater
according to my invention.
Figure 5 being an end elevation thereof, and:
Figure 6 a plan of the same.
Figure 7 is a side elevation illustrating another arrangement of superheater:
Throughout the drawings the same letters of reference indicate corresponding
parts..
20
a is the boiler, a are the internal flues thereof, and a represents the boiler setting
in which are formed the external flues or smoke passages
bbare the steam boxes or chambers of the superheater. cc, are the tubes
thereof, the portions of which in proximity to the lower box are horizontal while
the portions extending behind the boiler up to the steam box are vertical, or
approximately so. Between these horizontal and vertical portions the tubes have
a gradual curvature, .e., a curvature of large radius, as indicated at e'. Tubes such
as described are very simple to manufacture and therefore permit of the super-
heater being made at a comparatively. low cost. There is moreover very little
liability of their becoming choked, and if such should happen, the gradual
curvature of the parts & admits of the passage through the tube' of 'devices' for
Jemoving the obstruction.
-
According to the arrangement shown in Figures 1 to 3 the steam is collected in
a suitable anti-priming pipe & whence it passes through a pipe e extending down
through the water space of the boiler and communicating with the lower steam
box or chamber 6 of the superheater by means of an elbow f. From this box the
steam passes through the tubes c, to the upper box or chamber 6, and is then led
through a flanged coupling to a tube having a horizontal portion' situated below
the water level,. and a vertical portion extending through the top of the boiler
shell; this latter portion communicating with the steam pipe by which the steam
is conducted to the place where it is to be utilized: In some cases however the said
steam pipe may be connected direct to upper steam box b', the tube
dispensed with."
*. •*
9 being
In the arrangement in question the superheater is of such a width or is 80
arranged in the boiler setting that it is heated by the gases from both internal
Inuitgek s 101 9 QUITE MODA QUARTs no padinoa (2)

page_text: flues a¹, which gases flow between and around the tubes c on their way to the
flues a³.
In the arrangement shown in Figures 4 to, 6 a superheater of similar construc-
tion to that above described is placed in rear of each internal flue at of the boiler,
the two superheaters being separated by a wall at, and being so arranged that the
steam to be superheated is caused to flow first through one superheater and then
through the other. For this purpose the lower steam boxes are connected together
at their adjacent ends by a flanged coupling or by loop pipe or other suitable
connections. The upper box of one chamber, say that to the left of Figures 5
and 6 receives steam from the boiler through a flanged coupling 63, such steam
passing down through the said left hand superheater and then up through the
right hand one. From the upper box or chamber b¹ of this latter superheater the
steam may be conducted through a flanged coupling to a tube arranged inside
the boiler whence it is led away through a stop valve in the usual manner.
steam may however if desired be led away from the superheater direct to be
utilized. Or the steam may be allowed to enter the box through a pipe 65 at
the top, the said pipe & being connected to any suitable part of the boiler.
The
In some cases the steam may be led to the lower box b of the left hand super-
heater, say through a pipe such as e (Figure 1), and be caused to flow up the left
hand superheater and down the right hand one, this being the converse of the
arrangement just described.
In the arrangement shown in Figure 7 the lower boxes 6 of the superheater
are situated in the wall separating the space immediately behind the boiler from
the main flue a and the superheater tubes extend close to the boiler near their .
curved parts e. The cover plates 6 of the said lower boxes are thus accessible
from the main flue a so that they can be easily removed when necessary. In
this case two superheaters may be employed with each boiler as in Figures 4 to 6.
The steam may be admitted to the upper box of one of the superheaters by a
connection 3 from the back end of the boiler, or by a connection with the boiler
at any other place and be led away direct from the upper box of the other super-
heater by a pipe y or it may be led away from the lower boxes of the superheater,.
or be introduced first into the lower boxes band be led away from the upper boxes.
It will be seen that with this arrangement the furnace gases pass twice between,
the superheater tubes as indicated by the arrows. In all the foregoing arrange-
ments, moreover, the disposition of the steam connections, and also the manner.
of leading the steam to and from the superheater either direct or through tubes
or pipes extending inside the boiler, admit of being varied in a number of obvious
ways without departing from the nature of my invention.
Having now particularly described and ascertained the nature of my said in-
vention and in what manner the same is to be performed, I declare that what I ⚫
claim is :-
The combination with a steam boiler, of a superheater arranged in the external
flue at the back end of the boiler, said superheater consisting of upper and lower
boxes connected by bent tubes, substantially as described.
wu
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.