Improvements in Stationary and Transportable Steam-generators of the Locomotive Boiler Type.
Year: 1896

page_text: Date of Application, 11th Nov., 1896
Complete Specification Left, 11th Aug., 1897-Accepted, 11th Sept, 1897
PROVISIONAL SPECIFICATION.
Improvements in Stationary and Transportable Steam-generators
of the Locomotive Boiler Type.
I, WILHELM SCHMIDT, of Ballenstedt on the Harz, in the Duchy of Anhalt,
German Empire, Civil-Engineer do hereby declare the nature of this invention to be
as follows:
It is a known fact that boilers with flame-, fire-, or heating-tubes, especially such of
the locomotive boiler type, produce a very wet steam. To dry this steam a variety of
arrangements has been devised, but only a few of the latter have met with a satisfying
result. As to superheating the dried steam in a somewhat high degree there exists
up to now one construction only that has overcome the extraordinary difficulties which
the problem in question offers the constructer. Said construction is fully shown and
described in the British Patent No. 23547/1895, but to avoid taking reference to said
Letters Patent I briefly explain at this place that in the prior steam-generator in question
the boiler proper consists of two paits which are connected by a chamber, and that each
of said parts is furnished with a flame-, fire-, or heating-tube, or a set of such tubes,
which are put into communication by said chamber; the latter contains the superheater,
and means are provided for regulating the action of the furnace-gases upon said super-
heater.
There is, unfortunately, one drawback in said prior construction, which resides in
the difficulty of furnishing existing boilers with that novel arrangement. The latter
may well be applied on building up a new boiler, but altering an old boiler in the
manner requisite brings a lot of great inconveniences with it. Moreover, said prior con-
struction does not allow of a general application. The object of my present invention,
therefore, is to combine boilers of the type or types afore mentioned in a simple and
practical way with, or more precisely, turn them into, superheaters (such that allow
of a regulation of the degree of superheating) without causing a change in the
essential parts of the boiler, or in the arrangement and configuration of said parts
respectively. Making steam-generators of the important locomotive boiler type
able to continually produce highly superheated steam out of all the wet steam
generated in great quantities by said boilers is the more valuable as in view of the
novel method of employing superheating steam as described in the British Patent
No. 18639/1896 (regulating the inlet-temperature of the superheated steam according
to the degree of filling) such steam may now be employed in all types of engines
without detriment for the cylinders of the same.
My present invention is based on the idea of using a portion of the fire-gases
streaming forth from the furnace or fire-box for directly superheating the steam,
in such a degree or measure as is made requisite by the particular mode of working

page_text: of the particular sort of boiler employed. For that purpose I arrange a comparatively
wide tube (called hereinafter the superheating tube) among the fire- or heating-tubes,
preferably among the upper of them, and I arrange within said superheating tube
either a bundle of pipes running parallel to the tube, or a coiled pipe or pipes having
the longitudinal axis of the coil or coils running parallel to the said tube. The
combined surfaces of the pipes are so determined that all the steam the boiler can
generate may be superheated up to the highest degree desired, if the passage of the
fire-gases through the superheating-tube is not lessened. I wish it, however, to be
understood that I do not restrict myself to arranging among the fire- or heating-tubes
just one superheating-tube only, but two or more of them may be employed, provided,
of course, the diameter of the boiler be large enough. In such a case the portion of
the furnace-gases deviated by and through the superheating-tubes divides into as many
separated currents as there are such tubes. By making use of several smaller super-
heating-tubes instead of one correspondingly larger one the passage of the deviated
furnace-gases through said tubes is delayed because of the greater friction offered by
the walls or surfaces of the said tubes, and the other i.e. main-portion of the furnace-
gases intended to produce the wet steam is thus least weakened. The regulation of
the degree of superheating is effected by regulating the quantity of the fire-gases
that pass through the superheating-tube or -tubes.
In the form of construction of my improved steam-generator as represented in
Figures 1 and 2 the boiler is provided with one superheating-tube only. a is said tube
which passes from the wall e of the fire-box to the wall i of the smoke-chamber, in the
same manner as do the fire- or heating-tubes o. The tube a contains a number of
U-shaped pipes arranged in a circle, in such a manner, that the curved connecting-
portions of the legs of said pipes lay radially, as distinctly shown in Figure 2. Said
curved portions are connected with, and supported by, a ring r, which is situated
within the rear end of the tube a, and protects the said portions of the pipes u
against the injurious action of the fire.
A casings forming two concentric chambers 81 82 and having fixed to its rear wall
a thick plate receiving the ends of the pipes u is held from the wall i by the
mediation of bolts z. The outer legs of the pipes u communicate with the chamber 8¹;
the latter communicates by means of the pipe m with the steam-space of the boiler,
or with the dome of the latter respectively, and the steam passes thus from the
chamber through the pipes u to the chamber 8. Whilst flowing through said pipes
the steam is superheated by. the fire-gases streaming through the pipe a. Said gases
enter first the longish space left between the inner legs of the pipes u, and they then
distribute among the latter, until they leave the tube a, and pass into the smoke-
chamber, through the annular space left between the seat of the tube a and the plate.
The longish space afore mentioned is important for the cleansing of the tube a, in
that it allows of easily and conveniently introducing a jet of steam, or another means
of or for cleansing, between the pipes m. The annular space, or, more precisely, the
front end of the pipe a, may be closed by means of a disk w situated upon and being
held by, the ends of the pipes u. The disk w may be displaced upon the latter.from
a lever 6 by the mediation of a rod d. The quantity of the fire-gases allowed to pass
through the tube a may thus be regulated according to the degree of superheating
required.
In the modified form of construction shown in Figure 3 the U-shaped superheating-
pipes are replaced by concentric pipes u u², resembling Field-pipes. In this case the
chamber s¹ is situated in front of the chamber 82; the front-ends of the pipes u¹ pass
through said latter chamber, and terminate into the chamber sl. The latter receives
the fresh steam through the pipe m, whereas the superheated steam is led away from
the chamber s². I wish it, however, to be understood, that the reverse way may also
be chosen. The regulation is effected in the same manner as above described. The
construction represented in Figure. 3 is intended especially for older steam power-
plants, in which the degree of superheating cannot be allowed to be high.
In cases, however, in which just a very high superheating is desired, and in which
consequently the superheating-pipes are to have a large area of surface in spite of their

page_text: being arranged within the comparatively small pipe a, without impairing an easy and
convenient cleansing of the latter and of said superheating-pipes, I make use of three
(or more) concentric series of pipes u³ u u³ (Figures 4 & 5) connected at the rear end
of the pipe a by means of a hollow ring r¹. The latter may well be replaced by a
number of separated radially arranged connecting-pieces, each of which puts a pipe u³
and a pipe u into communication with a pipe u³.
. In the form of construction shown (Figure 4) the pipes of the inner series u³ and
the pipes of the middle series are fed with fresh or wet steam from the chamber 8²,
whereas the superheated steam issuing from the pipes of the outer series us collects
within the chamber 8. The direction of the steam passing through the pipes us u
is thus opposite to the direction of the furnace-gases, whereas the steam passing
through the pipes u' flows in a direction equal to that of said gases. I wish it, how-
ever to be understood, that I do not confine myself to leading the steam only in the
way just described; the chamber s¹ may well be connected to the steam-space of the
boiler, and the chamber & may receive the superheated steam (compare Figure 1).
I wish it further to be understood, that instead of one of such or similar bundles of
pipes as formed by the pipes u' u u³ two or more bundles may be employed.
If the quantity of the steam to be superheated is but small, the straight pipes, or
the bundles of them respectively, may well be replaced by a coiled pipe u (Figures 6
and.7). The casing 8 (Figures 1, 3 & 4) is in this form of construction dispensed
with, and is replaced by a plate 82 held by the bolts z. The steam enters the coil
proper at u, and leaves it at u". The regulation is effected by the displaceable disk w,
in the same manner as described with regard to the other forms afore described; all
other details, as well as the mode of working, are or is so simple that I think I may
abstain from giving further explanations. In the whole it is to be seen that that type
of boiler which with regard to the problem treated has up to now offered the greatest
difficulties may now be changed into a superheating-boiler without any disturbing or
troublesome appendage.
Improvements in Stationary and Transportable Steam-generators
of the Locomotive Boiler Type.
I, WILHELM SCHMIDT, of Ballenstedt on the Harz, in the Duchy of Anhalt, German
Empire, Civil-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 :-
. It is a known fact that boilers with flame-,-fire-, or heating-tubes, especially such of
the locomotive boiler type, produce a very wet steam. To dry this steam a variety
of arrangements has been devised, but only a few of the latter have met with a
satisfying result. As to superheating the dried steam in a somewhat high degree
there exists up to now one construction only that has overcome the extraordinary
difficulties which the problem in question offers the constructer. Said construction
is fully shown and described in the British Patent No. 23547/1895, but to avoid taking
reference to said Letters-Patent I briefly explain at this place that in the prior steam-
generator in question the boiler proper consists of two parts which are connected by
a'chamber, and that each of said parts is furnished with a flame-, fire-, or heating-
tube, or a set of such tubes, which are put into communication by said chamber; the
latter contains the superheater, and means are provided for regulating the action of
the furnace-gases upon said superbeater.

page_text: There is, unfortunately, one drawback in said prior construction, which resides in
the difficulty of furnishing existing boilers with that novel arrangement. The latter
inay well be applied on building up. new boiler, but altering an old boiler in the
manner requisite brings many great inconveniences with it. Moreover, said prior
construction does not allow of a general application. The object of my present
invention, therefore, is to combine boilers of the type or types afore-mentioned in a
simple and practical way with, or.more precisely, turn them into, superheaters (such
that allow of a regulation of the degree of superheating) without causing a change in
the essential parts of the boiler, or in the arrangement and configuration of said parts
respectively. Making steam-generators of the important locomotive boiler type able
to continually produce highly superheated steam out of all the wet steam generated
in great quantities by said boilers is the more valuable as in view of the novel method
of employing superheating steain as described in the British Patent No. 13639/1896
(regulating the inlet-temperature of the superheated steam according to the degree
of filling) such steam may now be. employed in all types of engines without detriment
for the cylinders of the same.
My present invention is based on the idea of using a portion of the fire-gases
streaming forth from the furnace or fire-box for directly superheating the steam,
in such a degree or measure as is made requisite by the particular mode of working of
the particular sort of boiler employed. For that purpose I arrange a comparatively
wide tube (called hereinafter. the superheating tube) among the fire- or heating-
tubes, preferably among the upper of them, and I arrange within said superheating
tube either a bundle of pipes running parallel to the tube, or a coiled pipe or pipes
having the longitudinal axis of the coil or coils running parallel to the said tube. The
combined surfaces of the pipes are so. determined that all the steam the boiler..can
generate may be superheated up to the highest degree desired; if the passage of the
fire-gases through the superheating-tube is not lessened. I wish it, however, to be.
understood that I do not restrict myself to arranging among the fire- or heating-tubes:
just one superheating-tube only, but two or more of them may be employed, provided,
of course, the diameter of the boiler be large enough. In such a case the portion of
the furnace-gases 'deviated by and through the superheating-tubes divides into as
many separated currents as there are such tubes. By making use of several smaller
superheating-tubes instead of- one correspondingly larger one the passage of the
deviated furnace-gases through said tubes is delayed because of the greater friction
offered by the walls or surfaces of the said tubes, and the other, i.e. main-portion of
the furnace-gases intended to produce the wet steam is thus least weakened. The
regulation of the degree of superheating is effected by regulating the quantity of the
fire-gases that pass through the superheating tube or -tubes..
In the form of construction of my improved steam-generator as represented in
Figures 1, and 2, of the accompanying drawings, the boiler is provided with one
superheating tube only. a is said tube which passes from the wall e of the fire-box
to the wall of the smoke chamber, in the same manner as do the fire- or heating.
tubes o. The tube a contains a number of U-shaped pipes u arranged in a circle, in
such a manner, that the curved connecting-portions of the ends of said pipes lay
radially, as distinctly shown in Figure 2. Said curved portions are connected with,
and supported by, a ring r, which is situated within the rear end of the tube a, and
protects the said portions of the pipes against the injurious action of the fire.
A casing & forming two concentric chambers 81, 82, and having fixed to its rear wall.
a thick plate receiving the ends of the pipes u is held from the wall i by the
mediation of bolts .z.. The outer ends of the pipes u communicate with the
chambers; the latter communicates by means of the pipe m with the steam-space of
the boiler, or with the dome of the latter respectively, and the steam passes thus from
the chamber 8 through the pipes u to the chamber 82. Whilst flowing through said
pipes the steam is superheated by the fire-gases streaming through the tube pipe a.
Said: gases enter first the longish space left between the inner portions of
the pipes u, and they then distribute among the latter, until they leave the
tube a, and pass into the smoke-chamber, through the annular space left

page_text: between the seat of the tube a and. the plate x. The longish
The longish space afore
mentioned is important for the cleansing of the tube a, in. that it, allows
of easily and conveniently. introducing a jet of steam, or another means of
or for cleansing, between the pipes u m. The annular space, or, more precisely, the
front end of the tube pipe a, may be closed by means of a disc w situated upon and
being held by, the ends of the pipes w. The disc w may be displaced upon the latter
from a lever b by the mediation of a rod d... The. quantity of the fire gases allowed to
pass through the tube a may thus be regulated according to the degree of superheat-
ing. required.
In cases, in, which a very high superheating is desired, and in which consequently
the superheating-pipes are to have a large, area of surface in spite of their being
arranged within the comparatively small tube pipe a, without impairing an ensy and
convenient cleansing of the latter and of said superheating-pipes, I make use of
three (or more) concentric series of pipes (Figures 3, & 4.) connected at the
rear end of the tube pipe a by means of a hollow ring 1. The latter may well be
replaced by a number of separated radially arranged connecting-pieces, each of which
puts a pipe u and a pipe u into communication with a pipe w
In the form of construction shown (Figure 3) the pipes of the inner series u and
the pipes of the middle series u are fed with fresh or wet steam from the chamber 8³,
whereas the superheated steam issuing from the pipes of the outer series ' collects
within the chamber s'. The direction of the steam passing through the pipes u u' is
thus opposite to the direction of the furnace-gases, whereas the steain passing through
the pipes us flows in the sume a direction as equal-to that of said gases. I wish it,
however, to be understood, that I do not confine myself to leading the steam only in
the way just described; the chamber s may well be connected to the steam-space of
the boiler, and the cbamber & may receive the superheated steam (compare Figure 1).
I wish it further to be understood, that instead of one of such or similar bundles of
pipes as formed by the pipes a uus two or more bundles may be employed.
The
If the quantity of the steam to be superheated is but small, the straight pipes, or
the bundles of them respectively, may well be replaced by a coiled pipe u
(Figures 5 & 6). The casing (Figures 1 & 3) is in this form of construction
dispensed with, and is replaced by a plate held by the bolts .
steam enters the coil proper at u, and leaves it at 8. The regulation is
effected by the displacable disc w, in the same manner as described with regard
to the other forms afore described; all other details, as well as the mode of working,
are or is so simple that I think I may abstain from giving farther explanations. On
the whole it is to be seen that that type of boiler which with regard to the
problem treated has up to now offered the greatest difficulties may now be changed
into a superheating-boiler without any disturbing or troublesome appendage.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is :-
1. A boiler of the locomotive-type for superheating steam and regulating the degree
of temperature of the same, characterized by a set or sets, or coil or coils
of pipes u tubes-b (arranged in one or more superheating tubes of larger
diameter a) said pipes tubes being adapted to dry the steam whilst the latter
passes through them in a direction opposite to that of the fire-gases, and to super-
heat the dried steam whilst the latter passes through the said set or sets or coil or
coils of pipes tubes, in the same direction as the said gases, the latter being more or
less throttled, whilst passing through the-central-channel-or-flue-formed-by the said
tubes, or tubes a substantially as described.
2. A form of construction of the boiler characterized in Claim 1, in which the set
or sets of the superheating pipes tubes consist each of two or more concentric groups
the pipes tubes of which are connected on one side with a double chamber located in
the smoke chamber of the boiler, and connected on the other side by an annular
chamber or by supporting radial channels, or by curved or arched tubing, the connec-

page_text: tion being in either case such that the steam entering the inner or outer compart-
ment of the double chamber passes first through one or more of said groups in a
direction opposite to that of the fire-gases and then back through the remaining
group or groups, so as to enter the other compartment of the double chamber in a
superheated state, substantially as described.