Improvements in and connected with Steam Superheaters.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in and connected with Steam Superheaters.
I, GUSTAV HENKEL, of Wilhelmshöhe, near Cassel, in the Province of Hesse-
Nassau, German Empire, Engineer, do hereby declare the nature of this invention
to be as follows;-
-
This invention relates to superheaters with regulable adjustable grate, and
has for its object to provide for the arrangement of a superheater more especially
where a very limited space for such purpose is available. The invention described
hereinafter permits of the employment of a superheating device in the smallest
possible occupation of space or the smallest imaginable heating surface of the
heating body, and provides also for the attainment of a high superheating of
the steam. By the employment of a superheater of this description the possibilty
of obtaining a superheating of the steam is afforded also for such boilers, where
only a very limited space for the building in of the superheater in the region
of the fire-box is available..
As however, the attaining of such object is only possible by the influence of tho
most direct action of the fire upon the heating surface of the superheater, that
is to say at a position of the superheater, where the same is in closest proximity
to the fire, it becomes a necessity, to maintain the durability of the superheater,
that the same during the first firing up of the boiler or during pauses in the
use of the steam plant, that the said superheater may be so arranged that the
same shall be protected from the extreme heat of the fire, more especially from
the so-called pointed or direct flame, and in general that the capability of the
regulation of the heat towards the superheater shall be as nearly perfect as it is
possible to attain.
The above sketched problem has been solved in the manner hereinafter
described and shown in the drawing forming part of this specification, in which;
Figures 1 & 2 show a circular superheater constructed according to my inven-
tion in vertical section and plan, whilst
Figures 3 & 4 show a slightly modified shape of a superheater constructed upon
the same principle.
Proceeding to describe the drawing, I remark that within a ring a (Figure 1).
immediately enclosing the fire-space, said ring being of cast iron or cast steel a
tube spiral is cast in. Here may be remarked, that instead of cast iron a mix-,
ture of clay, fireclay and broken seggars, the so-called chamotte or chamotte
stone, may be employed as material for the said ring, in which case the spiral
would then be embedded in such chamotte.
As chamotte however, is not so good a conductor of heat, the heating surface,
where chamotte is used, would have to be larger.

page_text: Furthermore the said spiral could be replaced by channels inside the said cast
steel or cast iron ring, the said channels being formed to a superheater without
employing the previously mentioned wrought iron spiral but in this latter case,
a risk of a loss of steam, would exist not only by the possible presence of small
pores and cracks in such superheating body, but also by the diffusion or expan-
sion of a temporary but very high degree of heat exercised upon the superheater.
There are also, as will be apparent, technical difficulties in the proper construc-
tion of channels of so small a size, as would be necessary for such superheating
bodies.
On the other hand it could not also be seriously taken into consideration, to
construct uncovered spirals more especially with reference to the question of
their durability, nor would it be practicable to expose the bare tube spiral to
the action of the direct flame.
For this reason a fire-proof material such as is afforded for instance by wrought
iron, is absolutely necessary for the protection of the spiral. Furthermore it is
also apparent that the greater mass of metal" (when using the wrought iron
mantle or body) will also tend to protect the superheater from the great variation
of the heat caused by the unequal stoking of the fire. Thus the metal mass in
which the spiral is embedded, forms to a certain degree a kind of “heat-
accumulator."
In order to prevent too excessive an action of the fire upon the superheater,
ie, to optionally regulate this action or influence, the grate is provided with a
device which, by means of a simple hand manipulation, permits the adjusting
of the grate at any height within the ring a.
When the boiler is first fired up or stoked, the grate would be so placed that
its top edge or its upper edge would approximately close at it were, the ring a
whereby, as is apparent, the said ring a would be absolutely protected from the
pointed or direct flame.
When for the purpose of starting the engine, the steam valve is opened,
so that the ring receives the necessary cooling by the flow of steam into the
spiral, the grate should be allowed to sink and subsequently lifted or raised as
required, "when" the temperature of the steam again becomes too great.
The closed position of the ring must be assumed at a comparatively low height,
in order that when the grate is in its lowest position, that the attention to the
same may not be made too inconvenient.
If the superheater is so arranged as represented by Figures 3 & 4, riz. that
instead of the same being entirely of a closed shape, the latter is open at the
front (resembling in form that of a reap hook), the result would be:
1. The height would then not be dependent upon the position of the fire-
doors,
2. There would be convenient space to conduct the 'flow and return-pipes
from underneath, and yet have the same fully protected (see Figure 3).
whilst, when the ring is closed or when the superheater has an entirely circular
shape, the conducting of the water would have to be effected through a hori-
zontal tube 6 (Fig. 1) where it was desired to avoid the attachment of a projection
extending towards the inside which would have the effect of decreasing the size
of the grate.
The before mentioned closed circular shaped superheater possesses the advantage
that the tube cast in, can consist of a continuous spiral, whilst, as shown in
Figure 3, in the case of the open or reap-hook-shaped superheater, it would be
necessary to employ connectors or caps for the tubes of the return flow.
Notwithstanding the above, for existing boilers however, this last named con-
struction would be chosen, more especially on account of the possibility of the
convenient building in of the same. In general, it may be said that this last named
construction may be in some cases the only possibility with existing fire-box
tubular boilers to attain any considerable superheating, for the simple reason that

page_text: with the already excessively utilized waste-gases of the latter, such superheating
is not possible.
Although this last described superheater is in an especial degree suitable for
the last named type of boilers, yet the use of the same would be practicable as
an example for fire-tube boilers, in which cases the superheating frame would
be given a U-shape and would be open toward the fire-door.
Lastly the device for raising and lowering the grate could of course be effected
by various mechanism. Care only must be taken that the movement is such as
to avoid any binding which could be occasioned by one-sided pressure and fric-
tion upon the grate or upon the superheating frame. Furthermore, the
mechanism chosen, must not allow the grate to move in a slanting direction.
Also the actuating mechanism here in question must be exceedingly simple and
must not render the grate nor the ash box inaccessible for cleaning purposes.
These conditions I have fulfilled by means of the lever construction described
and shown in Figures 1 & 2.
This mechanism is as follows⚫
Two short shafts c c¹ with four levers grip the grate frame at four points
simultaneously, and raise and lower the same without any lateral pressure when
the hand lever is actuated; said hand-lever e by means of the diagonal rod f
and lever connecting the two shafts c and c¹.
As the two levers d d or more precisely, each set of levers d d move in an
opposite direction, all lateral pressure is removed, in consequence of which the
grate is lifted in a freely suspended condition.
PRE
JENSEN & SON,
77, Chancery Lane, London, W.C.,
Patent Agents.
improvements in and connected with Storm Supermeaters.
I, GUSTAV HENKEL, of Wilhelmshöhe, near Cassel, in the Province of Hesse-
Nassau, German Empire, 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 superheaters with regulable adjustable grate, and has
for its object to provide for the arrangement of a superheater more especially
where a very limited space for such purpose is available. The invention herein-
after described permits of the employment of a superheating device occupying
the smallest possible space or the smallest imaginable heating surface of the
heating body, and provides also for the attaining of a high superheating of the
steam. By the employment of a superheater of this description the possibility
of obtaining a superheating of the steam is afforded also for such boilers, where
only a very limited space for the building in of the superheater in the region of
the fire-box is available.
As however, the attaining of such object is only possible by the influence of
the most intense action of the fire upon the heating surface of the superheater,
that is to say at a position of the superheater, where the same is in closest
proximity to the fire, it becomes a necessity, to maintain the durability of the
superheater, that same during the first firing up of the boiler or during pauses
in the use of the steam plant, may be so placed or arranged that it is protected

page_text: from the extreme heat of the fire, more especially from the so-called pointed or
direct flame, and in general that the capability of the regulation of the heat
towards the superheater shall be as nearly perfect as it is possible to attain.
The above indicated problem has been solved in the manner hereinafter described
and shown in the drawing, filed with the. Provisional Specification, in which:
Figures 1 & 2 show a circular superheater constructed according to my inven-
tion respectively in vertical section and plan, whilst
Figures 3 & 4 show a slightly modified shape of a superheater constructed upon
the same principle.
Within a ring a (Figure 1) immediately enclosing the fire-space, said ring
being of cast iron or cast steel a tube spiral is cast in. Here may be remarked,
that instead of cast iron a mixture of clay, fireclay and broken seggars, the so-
called chamotte or chamotte stone, may be employed as material for the said ring,
in which case the spiral would then be embedded in such chamotte.
As chamotte however, is not so good a conductor of heat, the heating surface,
where chamotte is used, would have to be larger.
Furthermore the said spiral could be replaced by channels inside the said cast
steel or cast iron ring, the said channels being formed to a superheater without
employing the previously mentioned wrought iron spiral, but in this latter case,
a risk of a loss of steam, would exist not only by the possible presence of small
pores and cracks in such superheating body, but also by the diffusion or expan-
sion of a temporary but very high degree of heat exercised upon the superheater.
There are also, as will be apparent, technical difficulties in the proper con-
struction of channels cast in of so small a size, as would be necessary for such
superheating bodies.
On the other hand it could not be seriously taken into consideration, to con-
struct uncovered spirals more especially with reference to the question of their
durability, and it would not be practicable to expose the bare tube spiral to the
action of the direct flame.
For this reason a fire-proof material such as is afforded for instance by wrought
iron, is absolutely necessary. Furthermore it is also apparent that the greater
mass of metal (when using the wrought iron mantle or body) will also tend
to protect the superheater from the great variation of the heat caused by the
unequal steking of the fire. Thus the mass of metal in which the spiral is
embedded, forms to a certain degree a kind of "heat-accumulator."
In order to prevent too excessive an action of the fire upon the superheater,
i.e. to optionally regulate this action or influence, the grate is provided with a
device which, by means of a simple hand manipulation, permits of the adjusting
of the grate at any height within the ring a.
When the boiler is first fired up or stoked, the grate would be placed so high
up, that its top edge or its upper edge would approximately close as it were, the
ring a whoreby, as is apparent, the said ring a would be absolutely protected
from the pointed or direct flame.
When for the purpose of starting the engine, the steam valve is opened, so
so that the ring receives the necessary cooling by the flow of steam into the
spiral, the grate should be allowed to sink and subsequently lifted or raised as
required, "when" the temperature of the steam again becomes too great.
The usual working position of the ring must be assumed at a comparatively low
height, in order that when the grate is in its lowest position, the attention to
the same may not be made too inconvenient.
If the superheater is so arranged as represented by Figures 3 & 4, viz. that
instead of the same being entirely of a closed shape, it is open at the front
(resembling in form that of a reap hook), the result would be:
1. The height would then not be dependent upon the position of the fire-
doors,
2. There would be convenient space to conduct the inflow and return-pipes
from underneath, and vet have the same fully protected (see Figure 3).

page_text: whilst, when the ring is closed or when the superheater has an entirely circular
shape, the conducting of the water would have to be effected through a hori-
zontal tube (Figure 1), where it was desired to avoid the attachment of a
projection extending towards the inside which would have the effect of decreasing
the size of the grate.
The before mentioned closed circular shaped superheater possesses the advan-
tage that the tube cast in, can consist of a continuous spiral, whilst, as shown
in Figure 3, in the case of the open or reap-hook shaped superheater, it would be
necessary to employ connectors or caps for the tubes of the return flow.
Notwithstanding the above, for existing boilers however, this last named con-
struction would be chosen, more especially on account of the possibility of the
convenient building in of the same. In general, .it may be said that this last
named construction may in some cases be the only one possible with existing
tubular boilers in order to attain any considerable superheating, for the simple
reason, that with the already excessively utilized waste-gases of the latter, such
superheating is not possible.
Although this last described superheater is in an especial degree suitable for
the last named type of boilers, yet the use of the same would be practicable as
an example for fire-tube boilers, in which cases the superheating frame would
be given a U-shape and would be open toward the fire-door.
Lastly the device for raising and lowering the grate could of course be effected
by various mechanism. Care only must be taken that the movement is such
as to avoid any binding which could be occasioned by one-sided pressure and
friction upon the grate or upon the superheating frame. Furthermore, the
mechanism chosen, must not allow the grate to move in a slanting direction.
Also the actuating mechanism here in question must be exceedingly simple and
must not render the grate nor the ash box inaccessible for cleaning purposes.
These conditions I have fulfilled by means of the lever construction described
and shown in Figures 1 & 2.
This mechanism is as follows:-
Two short shafts c c¹ with four levers and links & grip the grate frame at four
points simultaneously, and raise and lower the same without any lateral pres-
sure when the hand lever is actuated; said hand-lever e by means of the diagonal
rod f and lever g connecting the two shafts c and c¹.
As the two levers d d or more precisely, each set of levers d d move in an
opposite direction, all lateral pressure is removed, in consequence of which the
grate is lifted in a freely suspended condition.
Having now particularly described the nature of my said invention, and in
what manner the same is to be performed, I declare that what I claim is:-
1. In a steam superheating device, in which the superheater proper can itself
be heated by the flames of a furnace, the combination with the superheater
proper of a movable grate adapted to be vertically adjusted with regard to said
superheater and means for thus operating said grate, for the purpose as described.
2. In a steam superheating device in which the superheater proper can itself
he heated by the flames of a furnace, the combination with the superheater proper
of a movable grate, surrounded by said superheater, and adapted to be raised
or lowered in the same, and means for operating said grate, for the purpose as
described.
3. In a steam superheating device, in which the superheater proper can itself
be heated by the flames of a furnace, the combination with a circular super-
heater having its superheating pipes enclosed in a vertical wall, of a vertically
movable grate, surrounded by said superheater, and means for maintaining said
grate at any height inside the said superheater, for the purpose as described.
4. In a steam superheating device, in which the superheater proper can itself
be heated by the flames of a furnace, the combination with the superheater
proper of a movable grate adapted to be vertically adjusted with regard to said

page_text: superheater; bell-crank levers located below said grate; links connecting the
latter to one arm of each of said levers, a rod connecting the other arms of said
levers, and means for operating the latter, for the purpose as. described.
בד
1
1941,
dor of Anril 1899.
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.