Improvements in or relating to Steam Superheaters.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in or relating to Steam Superheaters.
I, LEBRECHT STEINMULLER, of Gummersbach, in the German Empire, Manu-
facturer, do hereby declare the nature of this invention to be as follows:-
:-
In superheaters consisting of bundles or series of tubes the total area of the
cross section of the tubes is always greater than the area of the inlet-openings
to the superheater tubes. The steam having a tendency to take the shortest
path consequently it becomes unequally distributed among the separate super-
heater tubes which causes distributing variations of the temperature.
This invention seeks to avoid such variation by suitably throttling the steam
in its passage into the tubes. This throttling prevents the steam from entering
the nearest tubes immediately on its arrival in the superheater. The openings
of the tubes are reduced by suitable devices and the steam becomes consequently
uniformly distributed in all the tubes.
When working in a uniform manner the throttling of the steam or the reduc-
tion of the inlets may be constant, otherwise it is preferable to make the throttling
greater or smaller, according to circumstances. The devices used will be for
this reason fixed or invariable in the first case and adjustable in the second case.
The devices for reducing the tube-inlets may be advantageously arranged at
the inlet or outlet side or on both sides.
The devices used for reducing or damping the tube-openings consist either
of fixed rods tubes or like bodies projecting into the openings of the tubes or
secured therein, if desired, or of flap or slide valves or the like in front of them.
The closing devices have also an advantageous effect in case of the superheater
tubes bursting, as, in that case, the full area does not become free but only that
reduced by said devices. The result is that the steam spaces become emptied in
a comparatively slow manner.
Some examples of the devices for throttling steam according to the present
invention, applied to superheaters of various constructions will now be described.
In an arrangement of superheater in which the steam inlet chamber is divided
into two parts by a horizontal partition the steam comes in at the top, passes
through a series of tubes into the rear chamber and through a lower series..
tubes returns to the lower compartment of the first chamber.
of
The plugs for the openings in the wall of the chamber, through which the
superheater tubes are introduced, are provided with inward extensions reducing
the opening of the tubes. There are similar closing devices in the back chamber
for the lower series of tubes through which the steam returns. The steam entering
through the inlet chamber is forced owing to the plug rods etc. to enter the tubes
uniformly and is again forced to enter uniformly all the other tubes when chang-
ing its direction in the rear chamber, i.e. when entering the lower series of tubes.
The rod-like extensions of the plugs reduce the tube openings so that steam
is forced to pass through the narrow annular passages between the rod and tube,

page_text: In a modified construction the extension fits into the mouth of the tube, the
steam in this case enters through a central hole in the tubular extension or plug.
Another construction is similar to the preceding one, but the outlet from the
tubular plug is inclined at an angle so that the steam enters not in a straight
line, but at an angle with the wall of the tube. This causes an eddying or spiral
movement of the steam which is advantageous for taking up large quantities of
heat. In another form a rod-shaped closing device is employed which admits
steam through a helical groove like a screw thread into the tube and also com-
municates to it an eddying or spiral motion.
In superheater arrangements in which the throttling for non-uniform working
can be regulated the tube opening may be closed to a greater or lesser extent by
a slide provided with suitable openings and operated from the outside by means
of a rod or the like. In a modified construction caps are placed over the tube-
mouths and provided with throttle valves which can be all adjusted from the
outside by means of a rod. In a further modification conical valves or caps are
used secured to rods which latter are adjustable by means of screws or otherwise.
Dated this 22nd day of April 1898.
BOULT & WADE,
Agents for the Applicant.
I, LEBRECHT STEINMÜLLER, of Gummersbach, in the German Empire, Manu-
facturer, 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:-
In superheaters consisting of bundles or series of tubes the total area of the
cross-section of the tubes is always greater than the area of the inlet opening
to the superheater. The steam having a tendency to take the shortest
path, consequently becomes unequally distributed among the separate super-
heater tubes, which causes disturbing variations of the temperature.
This invention seeks to avoid such variation by suitably throttling the steam
in its passage into the tubes. The throttling prevents the steam from entering
preferably the nearest tubes immediately on its arrival in the superheater. The open-
ings of the tubes are reduced by suitable devices and the steam becomes consequently
uniformly distributed in all the tubes.
When working in a uniform manner the throttling of the steam or the reduc-
tion of the inlets may be constant otherwise it is preferable to make the throttling
greater or smaller according to circumstances. The devices used will be for
this reason fixed or invariable in the first case and adjustable in the second case.
The devices for reducing the tube-inlets may be advantageously arranged at
the inlet or outlet side or on both sides.
The devices used for reducing or damping the tube openings consist either
of fixed rods tubes or like bodies projecting into the openings of the tubes or
secured therein if desired, or of flaps or slide valves or the like in front of them.
The closing devices on the inlet and exit side of the several superheater tubes
have also an advantageous effect in case of a superheater tube bursting, as, in
that case the full area of two tube-sections does not become free but only those
reduced by said devices. The result is that the steam spaces become emptied in
a comparatively slow manner.

page_text: The accompanying drawings show some examples of the devices for throttling
steam according to the present invention applied to superheaters of various con-
structions.
Figures 1 and 2 show an arrangement of superheater in which the steam inlet
chamber is divided into two parts A and B by the partition T. The steam comes
in at A, passes through the series of tubes F into the rear chamber C and through
the series of tubes F1 returns to the compartment B of the first chamber.
The plugs D for the openings in the wall of the chamber, through which the
superheater tubes are introduced, are provided with inward extensions E reducing
the opening of the tubes. There are similar closing devices in the back chamber Č
for the lower series of tubes F1 through which the steam returns. The steam
entering through the inlet chamber A is forced, owing to the plug, rods etc. E
to enter the tubes Funiformly and is again forced to enter uniformly all the
other tubes when changing its direction in the rear chamber C, i.e. when entering
the lower series of tubes F.
If the exits of the superheater tubes are reduced together with the inlets by
the devices shown, only as much steam can escape, if a tube bursts, as corresponds
to the reduced area of the inlet and exit side of one tube.
Figures 3 and 4 show a similar superheater arrangement but with returning
tubes and with reduction devices in the inlet openings.
Examples of the extensions of the plugs D used in the superheaters described,
are shown in different constructions in Figures 5 to 12, and in Figures 5 to 6*.
The simplest constructions are those in Figures 5 and 6 and 5* and *. Here
the rod-like extensions E of the plugs I reduce the tube-openings F so that steam
is forced to pass through the narrow annular passages El between the rod and
the tube. In the construction according to Figures 7 and 8 the extension E fits
into the mouth of the tube, the steam in this case enters through a central hole G
in the tubular extension or plug.
The construction shown in Figures 9 and 10 is similar to the preceding one,
but the outlet G¹ from the tubular plug is inclined at an angle so that the steam
enters not in a straight line, but at an angle with the wall of the tube. This
causes an eddying or spiral movement of the steam which is advantageous for
taking up large quantities of heat. Figures 11 and 12 show a rod-shaped closing
device which admits steam through a helical groove H like a screw thread into
the tube F and also communicates to it an eddy or spiral motion.
Superheater arrangements in which the throttling for non-uniform working
can be regulated, are illustrated in Figures 13 to 19. In the construction shown
in Figures 13 and 14 the tube openings are closed to a greater or lesser extent
by a slide X provided with suitable openings and operated from the outside by
means of a rod K or the like. The construction shown in Figures 15 to 17 shows
an arrangement of throttle valves Y the pivots of which are secured to rings
mounted on the tube ends, said valves being operated by links and rods O which
latter pass through the chamber A and can be operated from without by means
of a screw K or similar device. In a further modification represented in Figures 18
and 19 conical valves or caps Z are used secured to rods N which latter are adjust-
able by means of screws K or otherwise.
Having now 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. Means for avoiding variations of temperature in steam superheaters,
characterised by the reduction of the inlet or outlet passages, or both of super-
heater tubes without reducing the cross sectional area of the main portions of
the tubes, so that the entering steam is throttled only at the inlet or exit end F
or both, of each tube for the purpose of obtaining a uniform distribution or
reduction of pressure.
2. Means for reducing the inlet or outlet passages or both of superheater tubes

page_text: comprising extensions of the closing plugs for the openings in the chamber walls.
opposite the tubes, said rods or tubular extensions entering and reducing the cross
sectional area of the tubes only at the inlet or exit ends, or both, of each tube,
substantially as described.
3. Means for reducing the inlet or outlet passages or both of superheater tubes
comprising adjustable slides, flaps, valves or the like for reducing the area of
the tube inlets or outlets without reducing the cross sectional area of the main
portions of the tubes substantially as described.
4. Means for reducing the inlet or outlet passages or both of superheater tubes
comprising tubular or grooved rods inserted in and filling the ends of the tubes
without reducing the cross-sectional area of the main portions of the tubes sub-
stantially as described.
5. Means for reducing the inlet or outlet passages or both of superheater tubes
substantially as described or illustrated in Figure 1 or in Figure 3 or in Figures 5
and 6 or in Figures 5 or 6 or in Figures 7 and 8 or in Figures 9 and 10 or in
Figures 11 and 12 or in Figures 13 and 14 or in Figures 15, 16 and 17 or in
Figures 18 and 19 of the accompanying drawings.
Dated this 22nd day of June 1898
LEB. STEINMÜLLER.
Boult & Wade,
Agents for the Applicant.