IMPROVEMENTS IN STEAM ENGINES AND IN BOILERS FROM WHICH SAID ENGINES CAN BE WORKED
Year: 1877

page_text: PROVISIONAL SPECIFICATION left by Henry Pierre Rieth at the Office of the
Commissioners of Patents on the 5th April 1877.
HENRY PIERRE RIETH, of Antwerp, Belgium.
IMPROVEMENTS IN STEAM ENGINES
AND IN BOILERS FROM WHICH SAID ENGINES CAN BE WORKED." (A communication
from abroad by Thister Reiner Rieth, of Bonn.)
It is a well-known fact among engineers that in practice 5 per cent. only, or about
a twentieth part, of the heat that coal can produce, according to theoretical calcula-
tions, is actually transformed into motive power, and that consequently 19 kilos. of
coal out of every 20 are entirely lost.
It may with certainty be stated that the theoretical efficiency of coal will never
be practically realized, but the numerous attempts that have been made in this
direction, and partly with success, show that a diminution of this enormous loss of
heat is considered possible, and remains to be realized.
The object of this Invention is to reduce to a minimum the most important cause
of this loss of heat. This cause is due to the fact that the large amount of air
which passes into the furnace, added to the products of combustion, leads away in a
useless manner into the atmosphere a large quantity of heat. To give an idea of
the enormity of this loss it is sufficient to state that in well constructed boilers of
marine engines the temperature of the products of combustion arriving in the
chimney is raised to 250 degrees centigrade, and that it attains even 300 degrees in
some boilers.
This temperature is sufficient to produce again at least the same quantity of
vapour at the same pressure as that of the steam already produced in the steam
boiler, and that by employing it to vaporize a hydrocarbon, the point of ebullition
of which is about 60 degrees.
Theoretically speaking, it may be admitted that the temperature of the products
of combustion in the furnace thus employed to vaporize a hydrocarbon will be
lowered to 100 degrees of heat; there will consequently have been an absorption of
heat of from 200 to 300 degrees, heat which will have been employed to produce
motive power. A hydrocarbon of any point of ebullition desired may be used. It
will of course be best to employ one whose point of ebullition is as low as possible
on account of condensation.
To the objection of danger from fire it is sufficient to state that nowadays boilers
are made perfectly steam-tight, that stoam coming out of a little opening could not

page_text: take fire because it would not directly touch the flames. In addition to this, in
employing dry boilers, that is to say, without liquid, the total quantity of hydro-
carbon stored will be so small that there need be no dread of fire. This established,
my Invention consists of the three following points :—
1. The production in steam engines of an ulterior force by the aid of the heat
still remaining in the gases or products of combustion after they have left the boiler
and have arrived in the chimney, being no longer at a sufficiently high temperature
to form steam.
2. The employment of dry boilers as hereafter described.
2 The amplowmant of a livdunarhon as a liauid to be vonovivad
To enable the Invention to be better understood, I will describe one application
of it by way of example. To an ordinary steam engine with steam boiler, &c., of
any construction, I add as a new part a second boiler destined to vaporize the
hydrocarbon liquid. This boiler, called "dry," is placed either behind the engine or
behind the fire boiler. The steam pipe of the hydrocarbon vapour boiler leads to
a second motor machine which in working puts into action a feed pump. The
vapour coming from the cylinder of the second machine enters a condenser cooled
from outside. With this arrangement the action of the apparatus will take place
as follows:
The gases escaping from the furnace after having left the steam boiler do not
enter immediately into the chimney as at present, but circulate round the outside of
the second boiler. At the same time each lift of the piston of the feed pump drives
back into the boiler a certain quantity of hydrocarbon liquid. This quantity is
measured exactly so that after its vaporization it is sufficient to produce the necessary
pressure to displace the piston in the steam cylinder. After the piston of the steam
cylinder has reached the end of its course the communication with the condenser
takes place by a valve. In this manner a vacuum is produced which in the return
course of the piston produces the same effect as in an ordinary condenser. At the
same time the feed pump takes at the proper time from the condenser the same
quantity of hydrocarbon liquid, and drives it back into the dry boiler in such
manner that the vapour from this latter when the piston returns produces a motive
force upon the other side of the piston. This action is repeated regularly as in all
ordinary condensers.
To avoid the bydrocarbon vapour cooling too much in the cylinder, or, on the
contrary, augmenting its expansion, it will be found useful to encase the steam
cylinder and the steam pipe of the second machine. In this casing the steam
coming from the first boiler is allowed to circulate. This last utilization of steam
presents a certain analogy to the proposition of Mr. Verdal, of Tremblay.
The steam from the first machine having been used inay also be led to a condenser
after having served to maintain the cylinder and the steam pipes of the second
machine warm, and consequently, whenever possible, it will be best to make the
first machine serve as a condenser. If this does not do, the steam may be added to
the gases from the furnace to increase the draft after having served as before stated.
With great care the point of ebullition of the hydrocarbon may be fixed once for
all for each machine, as only a small quantity of hydrocarbon will be consumed in
a constant circulation.
The second boiler, in which the hydrocarbon liquid evaporates, will be by
preference tubular to increase the heating surface. Being fed in proportion to the
evaporation there is no necessity for a safety valve, as the point of ebullition is
fixed and as the quantity of liquid contained in the boiler is limited, and it is certain
that after vaporization the pressure cannot exceed a certain limit. A level indicator
inside may also be dispensed with, and the test-cocks, since there is never any liquid
in the boiler.
Lastly. The boiler will not require rengiring because incrnatation will be

page_text: impossible and because the back plate cannot be destroyed by fire. For these
reasons in applying my Invention to marine engines, additional hydrocarbon boilers
can be placed in a separate place, and if once for all the fastenings have been care-
fully done, the boiler may be left to itself.
It is evident that caoutchouc or india-rubber must not be used for the joints, some
fire-resisting material, such as asbestos, being necessary.
The Invention may be applied with advantage to all machines which have at
their disposal sufficient water for condensing purposes, but it is especially applicable
to marine engines of all kinds because the advantage for them is double, seeing that
the expense of firing is saved and great room is gained.
The advantages of my Invention are:-
1. The power gained in applying it may be increased to a multiple of the original
power of the steam engine, and only uccessitates the expense of fitting and not of
working.
2. The danger of catching fire is done away with because the boiler will not
touch the fire, and because by reason of its acting in an isolated position it can be
placed in any closed or non-accessible place.
3. The temperature cannot exceed a given maximum because the quantity of
liquid and the temperature of it are limited, and by reason of this the danger of
explosion is excluded.
4. The boiler may be constructed having regard only to the pressure and to the
greatest possible surface, and in accordance with the most complicated systems of
boilers, with straight tubes or bent, which cannot be used for steam boilers by reason
of the difficulty of cleaning.
5. The boiler will never require repairing by reason of non-incrustation or fire
burning.
6. The construction of the boiler is most simple by reason of its acting dry,
requiring no level indicator, nor manometer, nor safety-valve, nor man hole.