Improvements in Superheating Apparatus for Steam and other Fluids.
Year: 1899

page_text: Date of Application, 5th Dec., 1899-Accepted, 24th Feb., 1900
CUMPLEIN DIUINIO
Improvements in Superheating Apparatus for Steam and other
Fluids.
I, HUGO SZAMATOLSKI, of 13, Gutleutstrasse, Frankfort on Maine, Germany,
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 more particularly to steam superheaters of the kind in which
the steam bas imparted to it an accelerated motion proportional to the increase in the
temperature thereof.
In the existing superheaters of this class, the said acceleration was produced by
means of conduit tubes of decreasing diameter in the direction towards the dis-
charge opening for the steam.
The present improved construction of superheaters on the other hand, is such that
the flow is entirely independent of the diameters of a series of conduit pipes
connected together so as to form a continuous channel.
By this means it is rendered possible not only to insure the uniform heating of the
superheating conduit pipes, but also, more particularly, to effect a much better utili-
sation of the hot combustion gases employed for heating, this being attained by so
arranging the superheating tubes (which may have the same or different diameters)
relatively to each other that the sectional areas of the passages for the heating gases
are substantially equal in all zones of the superheater, for which purpose, in the event
of this not being already insured by the superheating pipes themselves, that is, by
their relative positions, the object may be accomplished by a suitable arrangement
of the partition walls.
Should this not be possible in certain cases, special structures may be introduced
(such as plates), either in the gas flues or in the spaces between the superheating
pipes.
1
As a con-
With tubular superheaters having pipes of decreasing diameter towards the dis-
charge opening, and in which the reverse-current system is employed (which is
generally the case) the smallest pipes are situated at the inlet opening for the furnace
gases, which consequently there find a comparatively large sectional area for their
passage between the said small pipes, which area gradually diminishes in the inward
direction, owing to the gradual increase in the size of the pipes.
sequence, the combustion gases can in the first instance only come partially in con-
tact with the superheating pipes, namely, only that part thereof which comes into
direct contact with the pipes, the remaining portion of the gases flowing through
The utilisation of the
without exercising any superheating effect upon the steam.
heat of this portion of the gases is only effected at the inner part of the superheater,
where the spaces between the pipes are reduced by reason of their increased diameter.
Consequently it is only at this part that a tolerably effective utilisation of the heat of
the furnace gases is attained, while at the front part of the superheater such utilisa-
tion is imperfect; and in consequence thereof, the said gases leave the superheater at
much too high a temperature, so that the apparatus does not work economically.
In the present improved construction this defect is obviated by so arranging the
superheating pipes that, whether they are of large or of small diameter, each
pipe is made to utilise the heat of the furnace gases to the same extent, while

page_text: the latter are made to heat all the pipes to the same extent, whether they be large
or small.
By this means there results a material increase of the advantages which are obtained
by the said system of accelerating the flow of the steam in proportion to the increase
of temperature.
In carrying out the fundamental principle for the production of practically equal
sectional areas for the flow of the combustion gases in all zones of the superheater,
the steam conduit can be formed by pipe-groups having a decreasing number of pipes
in the direction towards the outlet of the steam, or the decrease of the total sectional
area of the steam conduit can also be effected independently of any decrease in the
number of pipes, that is, even with an equal or increasing number of pipes in each
group, by suitably determining the sectional areas of the separate tubes.
For the first above named case an example is shewn at Fig. 1 of the accompanying
drawings. There are here provided, in addition to the single pipe a, three groups of
pipes, of which the one next the pipe a consists of the two pipes b b¹, while the next
one consists of the four pipes c, c1, c2, c³, and the last group (which is the first in
respect of the direction of flow of the steam) of five pipes d, d¹, d², d³, d.
In this arrangement all the pipes are connected at both ends to the steam
chambers A A¹, in which are partitions A2, by means of which the division of the
pipes into the above named groups is effected. The steam chambers A A¹ are con-
sequently divided into separate compartments by these divisions, so that the steam
entering the chamber A at A3 is made to pass first into the group of five pipes d to d
in which the drying of the steam, and also a small degree of superheating thereof,
such as to 210° C., is effected; the sectional area of the pipes should for this purpose
be so calculated that the velocity of the steam therein amounts to about 15 metres per
second. The steam then passes out of the five pipes d to d into the four pipes c to c³
in which an increase of velocity takes place in consequence of the decrease of sectional
This speed is then double when the steam passes through the pipes b b¹,
and a
further doubling of the speed takes place in the pipe a, after which the steam, super-
heated to the required degree, issues at the maximum speed from the chamber A
through the outlet A+.
area.
The separate para'lel pipes can also be connected by the steam chambers if pipes of
varying cross section he connected in series such as either decreasing or increasing or
partly decreasing and partly increasing section. With this arrangement however, the
leading of the steam from one tube into another, or from one tube into a set of tubes
or from one set of tubes into another set; is not effected by the steam chambers, but
there are arranged within these special leading caps which also form part of the present
invention.
These caps are subject to steam pressure both from the steam pipes and from the
steam chambers, and they are thus subject to an equilibrium of pressure, as the same
pressure exists both inside and outside them. Such an arrangement is shewn by way of
example at Figs. 2 to 5 of the drawings in connection with a superheater whose pipe
groups have pipes of very different sectional area, so that the requisite decreasing
total sectional area of the pipes is in this case obtained, independently of any decrease
in the number of pipes, by a suitable proportioning of the sectional areas of the separate
pipes.
The steam entering the chamber A Fig. 2, through the branch pipe A³ passes
first into the four pipes g, g', 92, 93 and from these through the guiding
caps e shewn in dotted lines in plan at Fig. 5, into the four pipes f, having a
smaller sectional area than the pipes g, the caps e being in the lower steam
chamber A¹
The upper steam chamber A has four guide caps e¹ shewn in plan at Fig. 4, by
means of which each of the pipes f is connected in such manner to two considerably
smaller pipes d d¹...d, Fig. 5, that these pipes d d¹... also form a pipe group,
through which the steam flows in one and the same direction, namely from abov
downwards.

page_text: Within the chamber A¹ only a single guide cap e², indicated in dotted lines Fig. 5,
connects the whole of the eight pipes d to d' with only two pipes c c¹, Figs. 3 and 5;.
which in their turn are connected by means of the cap es to a single pipe b. This is:
again connected within the chamber A¹ by means of the cap et with two smaller.
pipes a al from which the steam, superheated to the required high maximum
temperature flows at its highest speed. As regards the sectional area of the separate
pipes and the groups of pipes, the following is to be observed.
*Assuming the diameter of the vines a to g³ amounts to 125 m/m.
As will be seen the total sectional area decreases gradually from the pipes g to g³
to the pipes a and a¹, so that by this means the acceleration of the steam will be
obtained proportionately to the increase of temperature.
Another improvement consists in a guiding piece which is introduced into the super-
heating pipes. By means of this guiding piece, of which there may be several in one:
and the same steam pipe, every particle of the steam passing through the said pipe
will be forced to come in contact with the sides of the pipe, so as to prevent the
steam from passing through the pipe in such a manner that a central portion of the:
steam passes through without coming in contact with the superheating surfaces.. It
is for the purpose of causing this central column of steam to be directed against the
walls of the pipe that the guiding pieces are inserted, these being so arranged that:
they guide the steam on the one hand from the outside to the inside, and on the
other hand from the inside to the outside, so that the continual change of the two
layers of steam takes place, and consequently every portion of the steam is brought
under the influence of the heated walls of the tube.
Fig. 7 of the accompanying drawing shews a part longitudinal section through a
pipe with one of the said guide pieces, while Fig. 6 shews a cross section through
the pipe and insertion piece on line X-X of Fig. 7.
Each guide insertion piece consists of an annular tubular piece h¹ connected to a
single tube h of smaller diameter. The connection between h and h¹ being effected.
by separate channels 2. The annular piece ¹ fits closely against the steam pipe;
while the tube h being of smaller diameter, is some distance from the steam pipė.
If the steam, for example, passes through the pipe in the direction of the arrows, the
portion thereof which flows along the walls of the pipe will be caught up by the
annular piece h¹ and be led through the channels h² into the tube h, whence
the steam will pass along the central part of the pipe. On the other hand, the
portion of the steam which has been flowing along the central part of the pipe will

page_text: be deflected towards the walls of the pipe, as this steam will pass through the central
space of the annular tube and will pass through the spaces between the channels h²
to the outer side of the tube h. At the second and every following guide piece the
above described action will be repeated.
This action will also take place if the steam be led through the pipe in the contrary
direction.
The number of insertion guide pieces employed depends upon the length of the
pipe as also upon the velocity of the steam. In every case the introduction of such
guide pieces enables one to obtain a very uniform superheating of the steam, that is
to say, a very effective utilisation of the heat of the combustion gases. In other
words, the exchange of heat between the steam passing through the interior of the
pipes and the gases passing along the outer surface thereof, is effected in a
much more perfect manner by the use of these guide insertion pieces than
without them.
This will also be the case when the pipe d is not actually used for superheating
steam passing through it, nor when the pipe is heated by combustion gases externally,
as this arrangement can be used not only for steam superheaters, but also generally
for any apparatus for the interchange of heat, such for instance, as for feed-water
heaters and the like.
An essential advantage of the above described construction as compared with
known apparatus is to be found in that the said guide insertion pieces only produce
throttling of the steam to a minimum extent. The sectional area of the steam pipe
or the like is only narrowed to an extent corresponding to the thickness of the walls
of the annular tubular piece h¹ and the passages h².
Having thus particularly described and ascertained the nature of this
invention and in what manner the same is to be performed, I declare that what I
claim is
1. In superheating apparatus wherein the steam or other fluid has its velocity
accelerated in proportion to its increase of temperature, causing the heating of the
fluid to be effected uniformly independently of the diameters of the superheating
pipes by means of such an arrangement of the said pipes, whether of equal or
of unequal cross section, and, if necessary of the walls or partitions of the apparatus,
that the sectional areas of the passages for the heating gases shall be substantially
equal in all zones of the apparatus, substantially as described.
2. In apparatus for superheating such as is referred to in the First Claim, arranging
the conduit pipes for the steam or other fluid in groups having a gradually decreasing
number of pipes towards the outlet end, substantially as described.
3. .In apparatus for superheating, such as is referred to in the First Claim, effecting
a gradual decrease of the collective sectional area of the steam pipes independently
of any variation in the number thereof, by suitably proportioning the sectional area
of each separate pipe, substantially as described.
4. In apparatus for superheating, such as is referred in the First Claim, connecting
the superheating pipes at both ends to chambers containing the fluid to be super-
heated, the interior of the said pipes being connected together by guide caps fitted
over the ends of the pipes within the said chambers in such manner that the fluid
either flows.in succession through the several pipes or partly in succession, and partly
simultaneously through two or more thereof, substantially as described.
5. In tubular apparatus for heating steam and other fluids, more particularly
of the kind referred to in Claims 1 to 4, the use of guide insertion pieces for the
conduit pipes, consisting of an annular piece fitting the walls of the pipe, which
piece is connected by channels with a separate central tubular piece, substantially as
described. ..
Dated this 5th day of December 1800