Improvements in or relating to Steam Superheaters.
Year: 1898

page_text: Improvements in or relating to Steam Superheaters.
A communication by AUGUST HERING, of 17, Lauferthorgraben, Nuremberg, in
the Empire of Germany, Civil Engineer.
I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E., of the Agency for Foreign
Patent Solicitors, 6, Lord Street, Liverpool, and 6, Bank Street, Manchester, both
in the County of Lancaster, 118, New Street, Birmingham, in the County of
Warwick, and 322, High Holborn, in the County of Middlesex, Civil Engineer,
do hereby declare the nature of this invention to be as follows:-
The steam superheaters formed of separate tubes hitherto employed suffer from
the common drawbacks that the connections formed by means of flanges, sleeves
and the like, lie inside the fire chamber so that any leakage cannot be repaired
whilst at work, and in the case of heavy repairs in indirectly fired superheaters
the boiler connected therewith must be placed out of action.
These drawbacks are entirely removed by the invention hereinafter
described and shown in the accompanying drawings in which a steam
superheater is formed of a suitable. number of spirally curved simple tubes
which are connected with both the collectors b and c by connecting nozzles near
both ends as shown in Figures 1, 1, 1", and 2. The connecting flanges e of these
nozzles are outside the flue so that the fire gases cannot encounter the same.
The
steam superheaters are ordinarily connected with the second flue or with another
place in the fire flue which is otherwise traversed by suitable hot gases in steam
boilers of any form of construction. Consequently as will be seen from the example
shown in Figures 1 to 2, the furnace gases flowing from the furnace tubes must
pass through the open valve 0 arranged in and on the partitions s into the super-
heating chamber, thence through the same and through the valve p out of the
same into the second flue, because the partition which is formed as a regulating
flap or valve is closed. A regulation of the superheating of the steam may thus
be attained by only partially opening the valves o and and only partially closing
the valve, r. The steam superheater can be entirely thrown out of action if the
valves o and be closed and the valve of the partition opened so that the fire
gases follow their previous course. Thus by the arrangement of three valves the
superheater may be regulated, thrown into action or if desired entirely thrown out
of action.
The superheater may be employed with any suitable system of boiler and the
pipes a may assume a vertical, horizontal or other suitable position and the collect-
ing pipes and c be attached or arranged to correspond. Also instead of flanges,
sleeves or other suitable means of connecting may be employed.
The steam superheaters built into the space between the upper boiler and the

page_text: group of tubes all suffer from the circumstance that the superheater cannot be
entirely excluded from the action of the heating gases. These drawbacks are entirely
removed by the improved superheater shown in Figures 3 and 4 in longitudinal
section and plan respectively.
•
As may be seen in Figure 3 the masonry cover enclosing the group of tubes is pro-
vided with a chamber serving for receiving the superheater. The heating of the super-
heater takes place by the hot gases being caused to flow from under the draught
plate A through the opening in a partition B arranged at the end of the plate A
and through a valve Cover the two partitions d and e and over the superheater in
order to again fall on the group of boiler tubes through the valves F and G behind
the partition B from whence the gases after travelling over a further portion of
the boiler escape in the ordinary manner to the chimney. If the gases are not
to encounter the superheater, the valves C, F and G are closed and a valve H
opened which has for its result that the heating gases only encounter the group
of tubes of the boiler without being able to penetrate into the superheater chamber.
In order to be able to form in the superheater chamber as large a heating
surface as possible the under collecting pipe J is arranged approximately parallel
to the group of tubes by which means the result is attained that the longitudinal
spirals may be fitted or suited to the superheater chamber.
The form of construction shown in Figures 5, 6 and 7 has for its object to enable
spiral tubes in steam superheaters on the system herein before described to be con-
veniently removed if they become defective. For this object as shown the rear
wall W of the masonry enclosing the superheater is placed in its separate layers on
angle-irons and flat-irons f so that cach separate layer of masonry M may be
removed independently, whilst the middle partition necessary for guiding the
draught may be formed partly of the support U carrying the spirals S and exactly
filling up the intermediate space, and the crosspieces J fixed between the spirals.
The middle partition ends above in a plate Z fixed in the dome or vault, whilst
the closing of the same against the walls W W W is effected by means of
shaped pieces Z fixed in said walls. The walls W and We end within the
curves formed by the spiral tabes. Outside these curves the closing against the
wall W is effected by means of tongue pieces Z formed of flat irons let into
the separate courses of stone or masonry. These tongue pieces are of such thickness
that when turned 90° they may be conveniently withdrawn through the inter-
stices formed by the angle irons w. If a defective spiral S is to be removed, the
two flanges Fare first screwed off from the ends of the spiral tubes and then
the layer of masonry M opposite the defective coil, and eventually the short tongue
pieces connected therewith are removed, after which the coil may be con-
veniently withdrawn through the interstice formed by the portion of masonry M
which has been removed.
The method of heating the apparatus is as follows:
The hot gases pass in divided streams through the smoke valves X and X¹ into
the superheater chamber, then combine, and falling over the partition walls W3
and W which are only carried to half the height into the chamber R, pass under
the middle partition Z into the chamber R and escape therefrom through the
valves y and y over the partitions W and W. By this guiding of the draught
and the circumstance that the coils are arranged alternately to one another, all
the coils are encountered by the hot gases and thereby a higher useful effect is
attained,
In order however in the case of directly fired superheaters on the system herein-
before described to protect the tube spirals directly exposed to the fire, against a
too rapid destruction, the apparatus is divided by means of two blind flanges A
and A entirely shut off from one another as may be seen in Figures 8 to 10 and
the wet current of steam entering is split into two parts and the thus divided
current is conveyed into the apparatus at the points B and C in the direction
indicated by the arrow.
By this means there is attained first that both the coils I encountered by the

page_text: hottest gases and also those coils E surrounded by the coldest gases are filled
with wet steam which has for its result a greater saving of the coils and the
highest utilization of the fuel.
Dated this 18th day of Avonot 1000
Improvements in or relating to Steam Superheaters.
A communication by AUGUST HERING, of 17, Lauferthorgraben, Nuremberg, in
the Empire of Germany, Civil Engineer..
I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E., of the Agency for Foreign
Patent Solicitors, 6, Lord Street, Liverpool, and 6, Bank Street, Manchester, both
in the County of Lancaster, 118, New Street, Birmingham, in the County of
Warwick, and 322, High Holborn, in the County of Middlesex, 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:
The steam superheaters formed of separate tubes hitherto employed suffer from
the common drawbacks that the connections formed by means of flanges, sleeves
and the like, lie inside the fire chamber so that any leakage cannot be repaired
whilst at work, and in the case of heavy repairs in indirectly fired superheaters
the boiler connected therewith must be placed out of action.
These drawbacks are entirely removed by the invention hereinafter described
and shown in the drawings accompanying the Provisional Specification in which a
steam superheater is formed of a suitable number of spirally curved simple tubes a
which are connected with both the collectors and by connecting nozzles near
both ends as shown in Figures 1, 1, 1", and 2. The connecting flanges e of these
nozzles are outside the flue so that the fire gases cannot encounter the same. The
steam superheaters are ordinarily connected with the second flue or with another
place in the fire flue which is otherwise traversed by suitable hot gases in steam
boilers of any form of construction. Consequently as will be seen from the example
shown in Figures 1 to 2, the furnace gases flowing from the furnace tubes must
pass through the open valve O arranged in and on the partitions s into the super-
heating chamber, thence through the same and through the valve p out of the
same into the second flue, because the partition r which is formed as a regulating.
flap or valve is closed. A regulation of the superheating of the steam may thus
be attained by only partially opening the valves and p and only partially closing
the valve r. The steam superheater can be entirely thrown out of action if the
valves o and be closed and the valve of the partition opened so that the fire
gases follow their previous course. Thus by the arrangement of three valves the.
superheater may be regulated, thrown into action or if desired entirely thrown out
of action.
The superheater may be employed with any suitable system of boiler and the
pipes a may assume a vertical, horizontal or other suitable position and the collect-
ing pipes and c be attached or arranged to correspond. Also instead of flanges,
sleeves or other suitable means of connecting may be employed.
i
The steam superheaters built into the space between the upper boiler and the
group of tubes all suffer from the circumstance that the superheater cannot be

page_text: entirely excluded from the action of the heated gases. These drawbacks are entirely
removed by the improved superheater shown in Figures 3 and 4 in longitudinal
section and plan respectively.
As may be seen in Figure 3 the masonry cover enclosing the group of tubes is pro-
vided with a chamber serving for receiving the superheater. The heating of the super-
beater takes place by the hot gases being caused to flow from under the draught
plate A through the opening in a partition B arranged at the end of the plate A
and through a valve Cover the two partitions D and E and over the superheater in
order to again fall on the group of boiler tubes through the valves F and G behind
the partition B, from whence the gases after travelling over a further portion of
the boiler escape in the ordinary manner to the chimney. If the gases are not
to encounter the superheater, the valves C, F and G are closed and a valve H
opened which has for its result that the heating gases only encounter the group
of tubes of the boiler without being able to penetrate into the superheater chamber.
In order to be able to form in the superheater chamber as large a heating
surface as possible the under collecting pipe J is arranged approximately parallel
to the group of tubes, by which means the result is attained that the longitudinal
spirals may be fitted or suited to the superheater chamber.
The form of construction shown in Figures 5, 6 and 7 has for its object to enable
spiral tubes in steam superheaters on the system herein before described to be con-
veniently removed if they become defective. For this object as shown the rear
wall W of the masonry enclosing the superheater is placed in its separate layers on
angle-irons and flat-irons so that each separate layer of masonry M may be
removed independently, whilst the middle partition necessary for guiding the
draught may be formed partly of the supports U carrying the spirals S and exactly
filing up the intermediate space, and the crosspieces T fixed between the spirals.
The middle partition ends above in a plate Z fixed in the dome or vault, whilst
the closing of the same against the walls W1 W2 W3 W is effected by means of
shaped pieces Z 72 73 74 fixed in said walls. The walls W and We end within the
curves formed by the spiral tubes. Outside these curves the closing against the
walls W is effected by means of tongue pieces 7 formed of flat irons let into
the separate courses of stone or masonry. These tongue pieces are of such thickness
that when turned 90° they may be conveniently withdrawn through the inter-
stices formed by the angle irons w. If a defective spiral S is to be removed, the
two flanges are first screwed off from the ends of the spiral tubes and then
the layer of masonry M opposite the defective coil, and eventually the short tongue
pieces connected therewith are removed, after which the coil may be con-
veniently withdrawn through the interstice formed by the portion of masonry M
which has been removed.
The method of heating the apparatus is as follows:-
The hot gases pass in divided streams through the smoke valves X and X into
the superheater chamber, then combine, and falling over the partition walls W
and W which are only carried to half the height into the chamber R, pass under
the middle partition % into the chamber R¹ and escape therefrom through the
valves y and y over the partitions W and W. By this guiding of the draught
and the circumstance that the coils are arranged alternately to one another, all
the coils are encountered by the hot gases and thereby a higher useful effect is
attained,
In order however in the case of directly fired superheaters on the system herein-
before described to protect the tube spirals directly exposed to the fire, against a
foo rapid destruction, the apparatus is divided by means of two blind flanges A
and A entirely shut off from one another as may be seen in Figures 8 to 10 and
the current of wet steam entering is split into two parts and the thus divided
current is conveyed into the apparatus at the points B and C in the direction
indicated by the arrow, i.e., the divided current entering at C below the blind
flange A, passes into and through the coils E, thence into the other collector below
the blind flange A and then through the oblique pipe connection to the collector

page_text: above the blind flange A thus joining the divided current entering at B, and both
currents flow thence into and through the coils D) to above A¹
By this means there is attained first that both the coils I encountered by the
hottest gases and also those coils E surrounded by the coldest gases are filled
with wet steam which has for its result a greater saving of the coils and the
highest utilization of the fuel.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed as communicated to me
by my foreign correspondent, I declare that what I claim is:-
1. A superheater having the connecting flanges (e) arranged outside the flue and
adapted to be tightened up whilst the apparatus is at work, substantially as herein-
before described.
2. In a superheater, the combination of a partition such as s, a partition
arranged as a valve such as r and valves such as o and so adapted that the
superheater may be regulated, thrown into or out of action, and repaired without
interrupting its working, substantially as hereinbefore set forth.
3. In a superheater, the combination of partitions such as A, B, D and E and
valves such as C, F, G and H, so adapted that when the valves C, F, and G are
opened the hot gases are deflected from the group of boiler tubes by means of the
partition 13 and forced to pass over the superheater by the partitions D and E
before they again encounter the group of boiler tubes through the valves F and G,
whilst when the valves C, F and G are closed and the valve H opened the hot
gases are prevented from penetrating into the superheater chamber and only
encounter the group of tubes of the boiler, thus allowing of the superheater being
thrown out of action, substantially as herein before set forth.
4. In a superheater, the combination with the masonry, of angle irons such
as w, flat irons such as f and tongue pieces such as adapted to enable each
separate layer of masonry to be removed and the separate spirals or coils of the
superheater conveniently withdrawn, substantially as and for the purposes herein-
before set forth.
5. An easily removable superheater comprising a series of partitions dividing
it into six chambers, a portion of the said partitions being formed by supports
such as U and cross pieces such as T in combination with masonry having angle
irons such as w and flat irons such as f between its separate layers and tongue
pieces such as adapted to enable each separate layer of masonry to be removed
and the separate spirals or coils to be conveniently withdrawn substantially as and
for the purposes hereinbefore set forth.
6. A directly fired superheater divided into two separate divisions by blind
flanges such as A and A¹ so as to divide the current of steam and cause both the
hottest and the coolest gases, to come in contact only with the heating surfaces
through which wet steam passes, substantially as and for the purposes hereinbefore
set forth.