Improvements in the Generation and Superheating of Steam for Steam Engines, and in Apparatus therefor.
Year: 1893

page_text: Date of Application, fat Feb., 1893
Complete Specification Left, 23rd Nov., 1893—Accepted, 13th Jan., 1894
PROVISIONAL SPECIFICATION.
Improvements in the Generation and Superheating of Steam for
Steam Engines, and in Apparatus therefor.
I, WILHELM SOHMIDT of Villa Henkel, Wilhelmshöho near Cassel, in the
Province of Hesse-Nassau, German Empire, Civil Engineer, do hereby declare the
nature of this invention to be as follows :—
My invention relates to an improved method of superheating steam according to
which the steam is heated near the cylinder as much as possible and the process
of superheating may be set about for several engines in such a manner, that
different degrees of superheating are reached in time even at different pressures of
the steam.
In my improved construction a complicated system of pipes is not required and
any loss of heat is effectually prevented.
My invention will be more readily understood by reference to the accompanying
drawing, in which :
Fig. 1 is. a longitudinal sectional elevation of any improved superheater in simple
construction.
Fig. 2 shows a longitudinal section of the superheater in a compound engine.
Fig. 3 is the sectional view of the valve arranged at the superheater.
Similar letters refer to similar parts throughout the different views.
The superheating of the steam is offected by steam of 50-60 atm., generated in
the spiral tube a, heated direct by a furnace. The steam evolved in spiral tube a
is made to pass through the pipe & and thereby conveyed to the spiral tubes co¹³
Burrounded with a double casing which the steam, evolved in the boiler, enters by
the nozzle d. The ateam, when heated by the spiral tubes co¹ o' leaves the casing
by the nozzle e. The cooled steam and the condensed water are reconveyed from
the tubes c c'e' to the spiral tube a by the pipe f.
Thus, steam of high pressure is continuously evolved within a closed system of
tubes, the upper part of which only serves for delivering heat to the steam to be
superheated.
The apparatuses, constructed in the described manner, may be fitted up easily close
by the steam-engine.
The superheater is still connected with a dlovice serving to lend off indirectly the
excessive heat and, at the same time, to control the water-level in the heating
spiral tube a.
Between the upper part of the pipe and the upper part of the pipe b there is
an intercalory serpentine pipe 9 connected with the pipes and b by the tubes g'
and and surrounded with a water-tank generally opened above.
The upper end of the tube is generally closed by a valve-cone (Fig. 3)
connected with the membrane by means of a pole it, the weight-lever bearing
on the membrane i”.
The mode of oporation of this dovico is the following:
If, by the heating of the spiral tube a, any steam is evolved, that part of this
steam, which rises in the serpentine-pipe g, is precipitated therein by the cooling of
the water, and the pipe g is thus generally filled with a water-column reaching to
the valve i, the normal water-line in the spiral tube a being above the connection
of the pipe g¹ with the tube a.
Any air entered is removed by particular contrivances well known before setting
the machine in operation :

page_text: At any increase of pressure within the heating spiral-tube a, effecting f. by the
diminution of the heat requisite for the stiperheating of the steam, the membrane
is raised and thereby the valve i opened according to the effective pressure and the
weight & pressing on the membrane. Hereby the water, contained in the pipe g,
is caused to sink to the level of the spiral tube a, the steam now entering from
above, when the valve i is opened.
Thus the excessive heat in the heating spiral-tube a is led off, the serpentine-
pipe working as cooler. If the excessive heat has been reduced sufficiently, the
membrane falls back, closing again the valve i, pipe g is filled with condensed
water and the working of the apparatus again begins in the same manner at the
next increase of the pressure. By the entrance of the steam into the pipe g steam
is evolved in the reservoir, the escape of which thus giving a signal, whon the
pressure in the heating spiral-tube a is too high. A whistle may be arranged in
order to render the signal more audible.
The device, just now described, only operates as long, as the lower opening of
pipe g is lying under water. If, however, this opening is situated 'freely, the
water-level of the spiral-tube a being sunk to the least allowable degree by
leakage etc., steam euters the serpentine-tube y from bolow, which is perceived not
only by the continuous escape of steam from out of the reservoir h, but by the
considerable depression of the steam in the spiral-tube a, the pipe g now acting as
cooler.
g
In this case the wanting quantity of water must be pumped up into the spiral-
tube a, in order to cause the normal working of the suporhenter.
Thus, a supornormal pressure may be in the spiral-tube without effecting any loss
of water, as in the common safety-valves, further the wator-level in the spiral-tube a
is precisely controlled.
In Fig. 2 the arrangement of my superheater is shown in a compound-engine,
and the appliance of my improved method in these engines has particular
advantages.
The high-pressure steam generated in the spiral-tube a' direct by a furnace,
passes through the pipe and partly enters the superheating spiral-tubes cª c²,
partly the superheating spiral-tubes c, c', then returning mixed with condensed
water by the pipe m to the heating spiral-tube a'.
The steam, coming from the boiler and entering at n, is at first heated by the
spiral-tubes c³c and then made to pass by the pipe o to the high-pressure cylinder p
of the compound engine. From here the used steam is conveyed by the tube 9 to
the spiral-tubes cc, superheating the steam again, which then enters by the pipe r
the low-pressure cylinders, leaving the same at t.
In this manner a twice superheating of the steam takes place close by the
engine from one fire-place and by means of two superheaters, the receiver being
replaced by the superheater e c².
.
The temperatures of the high- or low-pressure steam in my apparatus can be
regulated to one's liking.
In similar manner my superheaters may be employed in multiplex-engines.
Also in groups of engines, working with different pressures, particular super-
heaters for each engine may be arranged close by the same in such a manner, that
all these suporheaters are set in operation from one contral fire-place, yet admitting
a different superheating of the steam according to the different dimensious of their
spiral tubes.
My improved superheaters are also advantageously to be employed in hauling-
or in water-engines, in which till now a great loss of heat took place in consequence
of their slow working. These machines require therefore a higher superheating
than the common engines.
By means of the above described superheaters hauling- or water-engines together
with commnon steam engines may be supplied with steam from one central fire-
place, able to effect the requisite superheating of the respective motor.
1 do not confine myself to the exact form of the construction as shown in the

page_text: drawing, but the same may be modified, without departing from the nature of my
invention, in employing for instance other forms of tubes instead of spiral tubes
and substituting a tubular boiler for the spiral a or a¹.
Dated this 1st day of February 1893.
WILHELM SCHMIDT,
By Graham Binnie & Co.,
Agonts for the Applicant.
Improvements in the Generation and Superheating of Steam for
Steam Engines, and in Apparatus therefor.
1, WILHELM SCHMIDT of Villa Henkel, Wilhelmshöhe near Cassel, in the
Province of Hesse-Nassau, 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 :—
My invention relates to an improved method of superheating the steam for
steam-enginos, according to which method the steam is suporheated in the very
neighbourhood of the cylinder or cylinders of the engine, and the improved process
of superheating may be executed for several engines in such a manner, that
different degrees of superheating can be reached at a time, even at different degrees
of tension.
My invention will be more readily understood by reference to the drawings, left
with Provisional Specification, in which :—
Fig. 1 is a vertical longitudinal section through my improved superheater.
Fig. 2 shows a vertical longitudinal section through a modified superheater for
a compound engine.
Fig. 3 is a detail.
Similar letters refer to similar parts throughout the different views.
The superheating of the steam is effected by steam of 50–00 atm., generated in
the spiral tube a, which is heated directly by a furnace. The steam evolved in
spiral tube a is made to pass through the pipo h, and is thereby convoyed to the
spiral tubes e c' c' enclosed by a double casing, into which steam generated in a
boiler enters through the nozzle d. This steam, when superheated by the spiral
tubes o cleaves the casing through the nozzle e. The cooled steam and the
condensed water are reconveyed from the tubes e c'e' to the spiral tube a by the
pipe f
0
Thus, steam of high pressure is continuously generated within, and caused to
oirculate through, a closed system of tubes, the upper part of which only serves
for delivering heat to the steam to bo suporheated.
The superheating-apparatus, constructed in the described manner, may best be
arranged quite near to the cylinder or oylinders of the steam-engine.
I prefer to connect the superheater with a device serving to lead off indirectly
any excess of heat, and, at the same time, to control the water-level in the spiral
tube a.
f
Between the upper part of the pipe and the upper part of the pipe b, there is
arranged a coiled pipe g connected with the pipes and 6 by the tubes g' and g³,
Said coil being surrounded by a cooling-vessel h.
The upper end of tube is closed by a valve-cone i (Fig. 3) connected with
the diaphragm by means of a rod ♬ª¹; the diaphragm`being weighted by a
lever i
The mannor of working of this device is as follows:
A part of the steam generated in the spiral tubo a rises in the serpentine-pipe g
>

page_text: "
is, thus, generally filled with a water-column reaching up to the valve i, the normal
water-line in the spiral tube a, however, being above the connection of the pipe g'
with the tube f.
At any increase of pressure within the heating spiral-tube a, effected f.i. by the
diminution of the heat requisite for the superheating of the steam, the diaphragm ²
is raised, and the valve i, on account of its smaller surface, is opened according to
the effective pressure and the weight pressing on said diaphragm. The water,
contained in pipe g, is caused now to leave the latter, and to sink down on the level
of the water within the spiral tube a by the steam entering now through pipe g¹
and valve i z
Thus, any excess of heat arising in the heating spiral-tube a is led off, the
serpentine-pipe g working now as a cooler. If the excessive heat has been reduced
sufficiently and the pressure is fallen, the diaphragm regains its former position,
closing again the valve i; pipe g becomes filled again with condensed water, and
the apparatus will work in the same manner at the next increase of pressure. The
steam entering the pipe gheats the water in the reservoir h, so that the steam
evolved then by this water signalises, that the pressure in the heating spiral-
tube a is too high. A whistle may be arranged in order to render the signal more
audible.
The device above described, operates only as long, as the lower opening of pipe gl
lies below the surface of the water. If, however, this opening is freed by the
water-level of the spiral-tube a sinking to the least allowable depth, steam will
enter the serpentine-tube g from below, which, then, will be perceived not only by
the continuous escape of steam from the reservoir h, but by the considerable
depression of the steam in the spiral-tube a, the pipe g now acting again
as cooler.
In this case the quantity of water wanting must be pumped afterwards into the
spiral-tube a, in order to cause the normal working of the superheater.
In Fig. 2, I have shown my superbeater in connection with a compound-
engine; the employment of my improved method in these engines has particular
advantages.
The high pressure steam generated in the spiral-tube a' directly by a furnace,
passes through the pipe and enters partly the superheating spiral-tubes c¹ c',
partly the superheating spiral-tubos cc, returning then mixed with condeused
water through the pipe m to the heating spiral-tube a'.
The steam, coming from the boiler proper and entering at n, is first superheated
by the spiral-tubes and is then made to pass through the pipe o to the
high-pressure cylinder p of the compound engine. From here, the steam is led by
the tube g to the space containing the spiral-tubes c'e', and, after being superheated,
enters by the pipe r the low-pressure oylinder s, which the steam finally leaves
at L.
Also in groups of engines, working with different pressures, special superheaters
for each engine may be arranged close to the same in such a manner, that all these
superheaters are set in operation from one central fire-place, yet admitting a
different superheating of the steam according to the different dimensions or numbers
of their spiral tubes.
I do not confine myself to the exact form of the construction as shown in the
drawing, but the same may be modified, without departing from the nature of my
invention, in employing for instance other forms of tubes instead of spiral tubes and
substituting a tubular boiler for the spiral a or a².
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
olaim is :-
1. The method of superheating steam by leading the same over or around closed
pipes or coils or closed systems or groups of pipes or coils, in which steam of high ||

page_text: 2. The method of superheating steam for steam engines by leading the same over
or around closed pipes or coils or closed systems or groups of pipes or coils
arranged near to the cylinder or cylinders of the engine, the said pipes or
coils being filled with circulating steam of high pressure, substantially as described.
3. The method of superheating steam for steam engines by leading the steam
over or around closed pipes or coils or closed systems or groups of pipes or coila
arranged near to the cylinder or cylinders of the engine, the said pipes or coils
being connected at both ends with other pipes or coils or systems or groups of pipes
or coils which are exposed to direct fire, fire fire in which steam of high pressure is
generated, the said high-pressure steam flowing through the superheating pipes or
coils, substantially as described.
4. The method of superheating steam for groups of stoam-engines, for double-
cylinder or multiple-cylinder-steam-engines, or for double-cylinder or multiplo
cylinder steam-engines with expansion, especially compound-engines, consisting in
leading the steam for each cylinder over or around special pipes or coils or special
systems or groups of pipes or coils, arranged near to the respective cylinder or
oylinders of the engine or engines, the said pipes or coils for all these oylinders
being counected at both ends with other pipes or coils, or system or groups of pipes
or coils, which are exposed to the direct action of one fire, and in which steam of
high pressure is generated, the said high-pressure steam flowing through all the
superheating pipes or coils, substantially as described.
6. An apparatus for practising the method of superheating steam as characterized
by Claim 1, 2, 3 or 4, the combination with the furnace containing one or more
systems or groups of pipes or coils, with a receiver also containing one or more
Bystems or groups of pipes or coils, the pipes or coils of the furnace being connected
with those of the receiver, and the receiver being connected with a feed pipe for
the steam to be superheated and with a delivery pipe for the superheated steam,
substantially as described.
0. A regulating apparatus to be used in connection with the method of
superheating steam, as characterized by Claim 1, 2, 3 or 4, or with an apparatus as
characterized by Claim, the combination with a vessel containing a cooling
liquid, of a coiled pipe connected at its two ends with the two connections between
the high-pressure steam-generator and the superheating pipes, the upper end of the
cooling coil having an automatic valve opening at an excess of the respective
normal pressure, substantially as described.
Dated this 21st day of Namamba. 1900
WILHELM SCHMIDT,
By Robert Deissler,
Agent for the Applicant.