MOLTEN METALS USED AS A PRE- VENTIVE FOR THE ESCAPE OF STEAM AND VAPOUR WHILST STEAM AND GAS ARE USED AS A MOTIVE POWER
Year: 1875

page_text: LETTERS PATENT to Otto Trossin, of 41, Auf dem Häfen, Bremen,
Germany, for the Invention of "MOLTEN METALS USED AS A PRE-
VENTIVE FOR THE ESCAPE OF STEAM AND VAPOUR WHILST STEAM AND GAS ARE
USED AS A MOTIVE POWER."
PROVISIONAL SPECIFICATION left by the said Otto Trossin at the
Office of the Commissioners of Patents, with his Petition, on the
7th May 1875.
4 OTTO TROSSIN, of 41, Auf dem Häfen, Bremen, Germany, do hereby
declare the nature of the said Invention for "MOLTEN METALS USED AS A
PREVENTIVE FOR THE ESCAPE OF STEAM AND VAPOUE WHILST STEAM AND Gas are
USED AS A MOTIVE POWER," to be as follows:-
To use the fluid molten metal which shuts the steam in, there is a
simple upright engine required as at present used with the habitual
bearings. The construction only so far differs that as long as the

page_text: engine works it provides itself with the requisite shutting up or stopping
fluid.
In the cylinder which is larger in the middle than at both ends, there
is an air and water-tight piston attached to an arm, the piston is with
the exception of the upper covering entirely surrounded with the 5
shutting up or stopping fluid molten metal.
The stopping boxes are also surrounded with the stopping up fluid in
all those places which are to be air-tight; above the cylinder and gliding
box (schieberkasten) there is a reservoir into which the fluid which is
carried away by steam stream drops, and from whence it is conducted 1
back into the engine.
For the formation of the superheated steam a boiler with a super-
heated attached to it is used.
'
The superheater consists of several vapour-tight tubes screwed into
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Otto Trossin in the Great Seal Patent Office on
the 6th November 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, OTTO
TROSSIN, of 12, Blücher Strasse, Bremen, send greeting.
⚫ WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventh day of May, in the year
of our Lord One thousand eight hundred and seventy-five, in the thirty-
eighth year of Her reign, did for Herself, Her heirs and successors,
give and grant unto me, the said Otto Trossin, Her special licence
that I, the said Otto Trossin, my executors, administrators, and assigns,
or such others as I, the said Otto Trossin, my executors, admini-
strators, and assigns, should at any time agree with, and no others,
from time to time and at all times thereafter during the term therein
expressed, should and lawfully might make, use, exercise, and vend,
within the United Kingdom of Great Britain and Ireland, the Channel

page_text: feeble over heating of steam the cooling of the same by the cylinder does
not operate so hurtfully. The evaporation of the water carried along
with certainly produces a saving of coal, for if the water is carried into
the cylinder, the warmth which is needed for heating the water up to
the boiling point is entirely lost with full pressure machines, and in
machines of expansion partly. But the opinion that the hurtful
influence of cooling the cylinder is mitigated by an over heating of
steam is erroneous, for the higher the temperatur of the cylinder is the
greater will be the loss of warmth by employing the same metod of
filling the cylinder, and this loss cannot be avoided neither by employing
full steam nor by using overheated steam. On the contrary it is surc
that if the cylinder is not well wrapped up by a bad leader of warmth,
this loss will be greater by using of overheated steam, and this loss
cannot be made up by any property of steam.
The principal advantage of overheated steam is that for the pro-
duction of a certain volumen of overheated steam not so much water
needs to evaporate, because the warmth is used in a greater measure for
the extent of the steam. As for the encrease of the volumen with constant
pressure of steam by hightening its temperature proportionally little
warmth is needed, a greater saving of coal is easily to be comprehended.
An example in numbers will illustrate the above:-3 kilogramm of
water of 0° need 1952,195 units of warmth in order to form of it steam
of 4 atmospheres, the volumen of 3 kilo. of steam with 4 atmospheres
is = 1,428 cubic meter, the temperatur of this steam is 145°.
To produce 1 kilo. of steam of 4 atmospheres from water of 0° is
needed only the third part of the above warmth = 650,725 units of
warmth, the volumen of this steam is = 0,476 cubic meter; is this steam
overheated by 546° the same expands with constant pressure from
0,476 to 1,428 cubic metor. The bending of this overheated steam is
as mentioned, 4 atmospheres, and the temperature is 145°+546=691°.
In this overheating are used 262,353 units of warmth, consequently to
produce from 0° cold water 1,428 cubic meter of overheated steam of
4 atmosph. are used 650,725 + 262,353 = 913,78 units of warmth.
As we have seen above in order to produce from 0° cold water 1,428
cubic meter full steam are used 1952,175 units of warmth, consequently
the consumption of warmth in the formation of overheated steam is in
proportion to the consumption of warmth in the formation of full steam,

page_text: with the same volumen and power of expansion of 4 atmosph. equal to
1:2,138. In this calculation I made use of the coefficient of expan-
sion for permanent gas = 0,00 3665. The investigations on overheated
water steams by D'. Siemers, Fairbairn, & Fate, have proved that this
coefficient of expansion is much greater particularly near the point of
condensation of the steam, and with a greater heat comes near to
0,00 3665. In the expansion and cooling off of overheated steams
the steam will condense in a greater proportion than with permanent gass.
As the temperature of overheated steam as long as it remains in the
driving cylinder of the machine is still very high, it will operate there
more like a permanent gass and the greater condensation will work
at first in the condensator of the machine, but it does not work very
hurtfully but on the contrary very usefully on the motion of the
machine, everything being useful that produces a stronger condensation
of steam in the condensator. It is clear that half the coal can be saved
by employing overheated steam without regarding the saving, which is
produced by the evaporation of the water carried along with by the steam.
I should not have written all this had I not known that this description
is printed & sold by several Governments, wherefore I availed myself of
this opportunity to, contribute something to the knowledge of overheated
steam.
:
The advantages resulting from using overheated steam being very
considerable, many experiments have been made to use strong over-
heated steam in steam engines. These trials did not produce hitherto
the desired result, because there was to great a loss of steam. As the
specific wight of strong overheated steam is more then three times less
than the specific wight of full steam, the overheated steam consequently
escapes with equal pressure nearly twice as fast from any untight spot
of the machine. Add to this that by using full steam water is constantly
produced by cooling in the machine. This water hinders a good deal
the emanation of steam. As there is no water in the machine by using
of strong overheated steam, it is clear that with the least untightness of
the helm, the steam piston, the piston rod, etc., there must occur a great
loss of steam.
As fluids (to which of course steam & gas also belong) with the
same pressure stream out the more slowly the havier they are specificly,
it is necessary to stop the overheated steam by a fluid of a possibly large
specific wight from those parts of the helm, the piston, and the piston

page_text: For
rod which are to be made tight, to prevent the escape of steam. This
fluid I found in the smelted metals and theire mistures, which do not
decompose water steam at
a temperature of 500 - 600° C.
instance, lead, smelting point 323°; tin, 231°; bismuth, 260°; cadmium,
315° C., etc.
-
It is well known that the mixtures of these metals melt much easier,
pr. example, the mixture of 4 parts lead & 7 parts tin, at 170°; the
mixture of 2 parts bismuth, 16 parts lead; & 17 parts tin, at 158°; that
of 2 parts bismuth, 4 parts lead, and 3 parts tin, at 145°; that of 8 parts
bismuth, 5 parts lead, 3 parts tin, at 95°; that of 15 parts bismuth,
8 parts lead, and 4 parts tin, and 3 parts cadmium, at 65° C., etc.
An example in numbers will illustrate best the great atvantages
resulting from using liquid metals as a fluid for stopping steam. If a
machine should work without this fluid the strong overheated steam
would stream forth at an over pressure of 4 atmospheres, with a rapidity
of nearly 1000 meter in a second, from, any untight spot of the bar
(bolt), piston, etc. But if that steam should be stopped in the untight
spot by one of the metallic fluids above mentioned the steam cannot
escape; but should it press on it with an over pressure of 4 atmospheres,
and produce by it an overflowing of the same, the fluid would only
stream out under these circumstances with a rapidity of nearly 10,357
meter in a second, consequently about 95 times less then overheated
steam would have escaped under the same circumstances.
The accompanying Drawings represent the driving cylinders and slide
boxes of several machines intended for improving of much overheated
steam by means of this steam-expanding fluid, together with steam
boilers and plans for overheating apparatusses.
Fig. 1 showes a vertical section (Fig. 2 lateral section) of a steam
boiler, together with plan of an overheating apparatus. A tube to be
closed by a cut-off valve leads out of the steam room of the steam
boiler A to the tube a, and opens into A. Three curved tubes 6 come
out of it, and open each of them into a tube B, B², B². Out of the other
ends of these tubes also small curved tubes c lead to the tube d, and
open into it. The whole set of tubes are so screwed together by flanges
as to be steam tight, and are so walled in under the steam boiler that all
the flanges project over the walling. The ends of the tube B, the
tubes c & d, are packed with a bad conductor of heat (that is, not to

page_text: be combustible) held by the vessel e, in order to prevent this tube to
be cooled. is a fuel valve; g, fire-tube of the boiler; h, canal sur-
rounding the tube B.
Fig. 3 & 4 is likewise a walled-in boiler A; the fire gases pass
round it in the usual way. In the fire-box, the upper part of which is
enlargened, there are several retorts B, B, heated by the radiating heat.
The saturated steam is led out of the boiler by the tube a to the retorts.
It enters at b, b, and is led by the tube c, c, as far as the lower points of
the retorts in order to cool them, and thus to prevent theire being burnt,
the points being most exposed to the fire heat. By the tube d the over-
heated steam is led to the machine. About 16 inches over the grate e
there are two valves f, f. Two bars g, g, of the valves project out of the
walling of the fire-box, forming at a handle. The other extremities of
the bars 9, 9, are each of them in a metal bed walled in at i. By means
of the handle the valves may by a quarter turn be put out of the
horizontal position into a perpendicular position, and also the other way.
They being in a perpendicular may be brought into a horizontal position.
The valves are there for the purpose of preventing the retorts being
burnt, that is to say, if the machine stands still then the steam no more
circulates in the retort, so that these would become to much heated,
therefore as soon as the machine stands still, there being fire in the grate,
the valves must be laid into a horizontal position so as to keep the
radiating heat off from the retorts.
In order to form the valves two gratings made of wrought iron are
enclosed in fireproof clay, which clay, however, would not keep long
on the grating unless being peculiarly prepared. Take three parts of
fireproof clay that cements well, and mix it with iron wire 25 inch thick
and cut into pieces of 1 inch in length. With this clay so prepared
enclose the grating on each side to the thickness of 1 to 1½ inch, and
you will find that the clay will be lasting. Each valve is as long as the
fire-box, but only half so broad as the fire-box is broad.
Fig. 5 is a standing transportable boiler A, in which likewise a retort B
is used for the overheating of the steam. The retort is in a cylinder C,
whose wall only touches with an upper edge the bottom of the retort.
The outer diameter of the cylinder C is about by 5 inches less than the
inside of the boiler, consequently the wall of the boiler is everywhere
2½ inches distant from the wall of the cylinder. D is the fire-box, pretty
much enclosed by fireproof clay; a, a, are two valves serving the same

page_text: purpose, and made on the same principle as shown in Fig. 3. The
fastening is also the same, only differing in so far as the turning must be
made downward if they are to be put out of the horizontal into a vertical
position. The cylinder C is established in the following way:-A
number of wrought-iron staves bent in a right angle are fastened
to the plate e in such a manner as to be one inch distant from each
other. These staves are so enclosed in the above-mentioned clay mixed
with iron wire that they form a smooth cylinder. The fire gases rise out
of the fire-box into the canal d, d, which is produced by boiler &
cylinder wall, and then escape from here through the tube e into the
open air. Through the tubef the saturated steam is discharged into the
retort, and is then led into its point by the tube g. Out of the tube h
the overheated steam passes to the machine.
If you wish to produce steam in the boiler (Fig. 1) then open the
fire-tube of the boiler entirely by the slide f, which is done by pulling
at the rod i, thereby the canal is closed by the slide k, the two
slides f&k being firmly united to each other. When the fire in the
grate 7 has kindled, the fire gases pass through the fire-tube of the boiler,
enter into the canal in that surrounds the boiler, pass through it again
to the front, and thus get through the canal n into the chimney. If
the overheating apparatus is to be heated (which however must not be
done when the machine is working) the slide f must be opened about
half-way, or according to the degree of the overheating of the steam one
wishes to produce, even to ½ or ¼ of the way. Thus part of the fire
gases enter by the canal o into the canal h, where they heat the over-
heater, then pass through the slide k, then unite with the fire gases
comming from the fire-tube g, and with it pass through the canal m, then
escape likewise through the canal n into the chimney. Every time
when the machine is stopped the canal must be closed in order to
prevent the tube to be burned. At p, p¹, p², the tubes B, B', B³, are
partly enclosed in clay to avoid the operating of the small pointed
flame.

page_text: the middle at a; b is a plunger piston tighted by springs at c; the lid
of the piston continues like a tube downwards, and is at d united with
the piston rod e. The stuffing box f placed at the lid of the cylinder
surrounds the piston rod as far as g. When the piston is in its deepest
position the stuffing box still reaches pretty far into the lid of the piston.
The diameter of the stuffing box being less then the chamber into which
it is placed there is an empty space left round the stuffing box. Right
hand on the Drawing there is the stuffing box enlarged, so that there a
piped canal is formed leading through the cylinder lid and ending in
the stuffing box h, which is enlarged so as to form a vessel. This canal
can be closed by a screw valve.
In order to form the canal i for receiving the wall of the piston there
is a vessel m set in, furnished in the middle with a canal, which vessel
is shut from above by a reservoir n furnished with a canal in the middle:
The lid of this reservoir is full of holes as the bottom; round the reservoir
part of its wall is wanting, by which opening the inside of the reservoir
comminicates with the canal i. This canal is as broad again as the wall
of the piston is thick. The cross section of the canals of the reservoirs m
& n is by the cross section of a steam canal larger than the cross
section of the part of the piston lid reaching into the canals in order
that the steam may pass under the annular part of the piston lid.
The expansion of the machine is effected by a discharged valve s;
the discharging of the valve is effected by the fact of the diameter of the
valve rod not being much less than the diameter of the valve. To the
valve is cast a raised edge surrounding the stuffing box A. The fastening
plain of the valve is divided into two parts by a cavity leading round
round about the valve; out of this cavity a number of small canals lead
into the canal which is in the valve. This canal communicates by
several canals in the stuffing box t with the reservoir w; if the valve
rises then the canal z is closed, and thereby the flowing out of the liquid
is prevented.
In the slide box there is a bipartite slide whose steam canals 1 & 2
are extended as far as o. The upper part of the slide is broader on one
side; in its wall is the hollows 3 (indicated in the Drawing by dots);
opposite to this hollows there is in the wall of the cylinder a canal 4,
opening into the reservoir B; annother canal 5 leads into a reservoir A
(Fig. 7) cast to the slide box, and opens into it just over the bottom.

page_text: 6 is a small canal opening into the upper part of the cylinder. A
canal 7 (that can be closed by a valve 8 opening downwards) leads,
lengthened by a tube, to the valves (Fig. 6) and opens into the
reservoir w of the same. There is also in the wall of the cylinder a
canal 9.
The upper part of the slide is in a reservoir p; the stuffing-box for
the slide rod q reaches as far as in the reservoir. In a non-expansive
engine the canal 7, together with valve 8, is omited; the slide, as
shown in Fig. 8 & 9, is quite so arranged as above discribed, only it
is not here drawn bipartitely; Fig. 8 is a section from A to B of Fig. 9, 1
the designation of the parts is the same as in Fig. 7. There is a larger
vessel B (Fig. 6) screwed on cylinder and slide box lid; the worked up
steam of the machine is by a tube led into the reservoir B, from where
the steam escapes through a tube, which can be closed by a cut-off
valve into the open air or to the condenser of the machine, according to
how this is arranged..
From the slide box a tubo leads to the upper end of the cylinder, into
which it opens by means of a screw valve. Out of the upper extremity
of the cylinder (a canal, which can also be closed by a screw valve Z
(Fig. 6) leads down on the side of the cylinder, there it passes through
its bottom and opens in the reservoir m; C, a plate jacket serving to
envelope the machine in a bad heat conductor; D, a cast-iron jacket.
If you wish to set the machine to work, and if for this purpose you
want to make use of an alloy easily fusible, then close the cut-off valve,
which has been inserted in the conduit of pipes for the worked up steam, :
at the same time open the slide valve Z, then make the overheated
steam that has been developed before enter into the machine, leave it by
itself for about 15 minutes, and then it will be sufficiently warmed; then
get away the water that has gathered in the machine, close the screw
valve Z, open the above-mentioned cut-off valve, and get into the
reservoir B a liquid alloy melting at about 145°. Then set the machine
slowly, to work, and whilst the machine is working all the spaces
destined for receiving the liquid get filled.
The spaces to be filled with the metallic fluid in the machine are as
follows: Reservoir w of the valve s, vessel p in the slide box; then the
spaces surrounding the lower part of the slide, reservoir m, and canal i;
then the tube-like part of the piston lid and the enlargment a of the

page_text: cylinder. It is necessary to know the exact size of these spaces, and
thereby calculate the exact quantity of the fluid that is to be got into
the machine. When thus all is filled one may easily understand that
all parts of the machine that were to be cemented are surrounded by
fluid, whereby a practical closure is easily to be effected.
While the machine is working some fluid will allways get into the
cylinder by spots in the valve and slide that are not tight, and in a short
time there would be none left in the valves and round the slide if it was
not made up for, which is done in the following manner:-The metal
got into the machine by some slide that is not tight is led by the steam
current into the reservoir B, there suffered to fall, and from there again by
its gravity and the alternate pression in the upper part of the cylinder A,
again led into the valves and into the reservoir p. If the piston rises
there is only a feeble pression in the upper part of the cylinder, conse-
quently also in the vessel A. (Fig. 7), both parts being connected by the
canal 6 therefore the fluid rushes out of the reservoir B (Fig. 6), through
the canal 4, hollow 3 of the slide, through the canal 5 into the
reservoir A (Fig. 7). When the piston has arrived above and fresh
steam rises over it, then it also presses on the fluid in the reservoir A.
Now the slide has closed the canal 4 (Fig. 6), whereas it has opened the
canal 9, consequently now the fluid rushes out of the reservoir A (Fig. 7)
through the canal 5 (Fig. 6), hollow 3 of the slide, and through the
canal 9 into the reservoir p. While this is going on part of the fluid
flows also out of the reservoir A (Fig. 7) through the valve 8 which
opens canal 7, into the reservoir w (Fig. 6) of valves; when the valve s
closes the valve 8 is closed by the pressure on it which soon encreases.
By the closing of valves the reservoir w is also connected by the several
canals with the annular cavity 11, 11, so that also here the steam is cut
off by the fluid. It is evident that if such spots as are not tight in the
valves and the slide are not too considerable, they will be allways
surrounded with sufficient fluid, because every time the machine makes
a motion (rotation) the part that has escaped will be restored.
Fig. 10 is a standing expansion engine with hanging stuffing box.
Its construction being similar to that of the machine described in
Fig. 6, the Drawing will be easily understood; the valve motion (steam
distributor) is effected by an expansion slide of such a construction as
may be seen in the Drawing.

page_text: C
Fig. 11 is a lying expansion engine. A is the driving cylinder_which
is closed by the two lids (glands) a, a¹; both lids are hollow on the side
of the steam canals; the hollow b, b, have the same cross section as the
steam canals, and properly they form the continuation of them as far as
to the under part of the cylinder; here (as indicated at a in Fig. 12,
part of the walls is left out, and indeed to such an extent, that the
hollows with similar cross section communicate as the steam canals with
the cylinder A. The piston B is formed by a cylinder closed at one end
of more then half the length of the cylinder A; at c, c, it is made tight
by springs. A cylindrical vessel C is steam-tight, screwed to the lid a¹;
from the bottom of this vessel a tube leads trough an opening which
has been made for this purpose in the lid a¹; the tube is furnished at d
with a stuffing box; the cylinder C is a little flattened below that it
may here stand aloof from the piston to the hight of a steam canal.
.The outer diameter of the cylinder C is so much less than the inner
diameter, of the cylinder A that there is formed a canal in which just the
piston wall has room; e is the piston rod. On the cylinder A there is a
vessel D, Fig. 12, steam-tight, screwed to which by the tube is con-
nected with the steam exhaustin canal, and which also serves for
retaining of the metal which is torn away by the steam; ff, are the
slides which are surrounded by fluid metal as far as g; i, i, is a cavity
leading round about the cylinder A being connected by a canal with
the lower part of the slide box and is consequently likewise filled with
metal. Inside the packing there is a ring k which surrounds the piston
rod and whose outer and inner hollows are connected by canals, which
openings by a canal furnished with a cut-off valve are put into con-
nection with the under part of the slide box in such a way as that
the metal can get through the canal into the ring k which surrounds
the piston rod. At m also the small slide is cast to in order to lead
the metal out of the reservoir D into the slide box E.
When the machine stands still all the canals which lead off the
metal out of the slide box are closed by screw valves applied for that
purpose, so it will be seen that all parts of the machine that must be
made tight are surrounded by the metallic fluid during the time that
the machine is working. All stuffing boxes of the slide rods lying
deeper than the surface of the fluid no steam can come out but only
metal, besides this the steam pressing heavily on the metal in the slide
box the metal is forced to fill the whole cavity i and the space which is

page_text: between the two packings of the piston, consequently no steam can pass
over from one end of the cylinder (by spots that are not tight in the
piston, and of which there are allways larger and smaller ones) to the
other end of the cylinder, but it is also here cut off by fluid metal; it is
just the same with piston rod e. The parts which serve for employing
of the machine by means of steam, and which are mentioned in
discribing Fig. 6 are likewise applied in the machines, as reprensented in
Fig. 10 & 11, such as the cut-off valve which is inserted in the
conduit of pipes for the worked up steam, the two screw valves Z, the
tube leading from the slide box to the upper part of the cylinder, and
canal 16.
If you wish to make use of a machine, such as represented in Fig. 6,
10, & 11, which is to work with an alloy not easily to be melted or
with single metal, then I must expressly observe that you have to omit
the just here above-mentioned parts, serving to heat the machine by
means of steam, whereas you will have to enclose the cast-iron jacket D
(as represented by Fig. 6) with a canal 17 which is to be connected with
one of the first fuel canals, so that the fire-gas (regulated by a slide)
may draw round jacket D.
Before a machine of this kind is to be put to work you will make the
fire gas with the help of the slide spread round the jacket D, thus
warming the machine. The fire gas thus having done its service are
then let out under the boiler or into the open air. When the machine
is sufficiently warmed the fire gas is cut off from the machine, all the
rest is to be done as here above discribed.
Both kinds of machines when they are stopped and have become cold-
after having worked with a metal, they are likewise warmed in the
manner as here above described, and then can again be made a going.
There is no fear of the metal becoming too quickly cold in the machine,
the essays I have tried in this respect with a proof machine of 4 horse-
powers have turned out very favourable. The melting point of the alloy
I made use of in these trials was 145° C, the steam pressure in the
boiler was 3 to 4 atmosph.
First. I had the machine work with much overheated steam, then I
removed all the fire from the grate of the overheater (it had a firing of
its own where the counter current system had been applied, which, it
must be said, is the only right one) left the fire-grate open so that the

page_text: a, with stationary boilers, pro-effective horse power, for pit coal
firing 0,3 to 0,4 square meter, for wood and brown coal firing 0,4 to
0,06 square meter.