IMPROVEMENTS IN HEATING STEAM BOILERS OF STEAM SHIPS
Year: 1874

page_text: LETTERS PATENT to Alexander Friedmann, of Vienna, in the Empire
of Austria, Civil Engineer, for the Invention of "IMPROVEMENTS IN
HEATING STEAM BOILERS OF STEAM SHIPS."
Sealed the 28th July 1874, and dated the 29th January 1874.
PROVISIONAL SPECIFICATION left by the said Alexander Friedmann
r
at the Office of the Commissioners of Patents, with his Petition,
on the 29th January 1874.
I, ALEXANDER FRIEDMANN, of Vienna, in the Empire of Austria,
Civil Engineer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN HEATING STEAM BOILERS OF STEAM SHIPS," to be as
follows:-
This Invention has reference to the inconveniences resulting from
burning coals or other combustible matters in a number of fire-grates,
presenting together in a large steamer a surface of several hundred
square feet, and actuated by the natural draught of one or two low
funnels.

page_text: I construct in steam vessels a sort of a small blast furnace without
fire-grate, and which is filled with coals to which some lime has been
added in order to make the ashes of the said coals fusible, and which are
distilled and imperfectly burnt in the said furnace by air forced into it
by a fan or blower of any suitable construction. The gases arising from
the distillation and imperfect combustion of the coals, most of them
oxide of carbon, are intercepted or caught at the upper part of the
furnace as in iron blast furnaces in order that they may flow through
air-tight pipes to the fire-boxes of the boilers of the vessel and be burnt
there to heat the said boilers.
Periodically as often as a certain proportion of the coals or fuel of the
small blast furnace has been burnt a fresh quantity of coals is supplied
to keep the furnace filled. This is very simply effected by means of a
hollow horizontal half cylinder provided with two small axles and placed
on the top opening of the small blast furnace in such manner that the
coals deposited first in the said half cylinder are by turning the same
half round caused to fall into the furnace without uncovering the
opening.
The cylindrical part of the furnace is supported by an air reservoir
disposed around the bottom and partly conical part of the furnace so
that this latter part can be repaired without interfering with the upper
cylindrical part of the furnace. To allow the scoriæ to flow out periodi-
cally a small opening is formed near the bottom of the furnace. The
draught of the chimney of the steam vessels is assisted by a vertical screw
similar in form to the horizontal screw of screw steamers, and fitted in
the space of the chimney below or on the top of it so that the axle of
the screw may be in the axis of the chimney. It is rotated by a hori-
zontal steam engine, or it may be rotated by hand, especially when the
boilers are getting up steam.
To further facilitate the draught of the chimney I fit in the axis of
the chimney a steam nozzle of ½rd or rds of an inch, and even
nearly two inches in diameter, according to the diameter of the chimney.
The nozzle communicates by a pipe with the steam space of the steam
boilers similarly to the auxiliary small blast pipe of locomotives which
there has to increase the draught of the chimney when the locomotive
is not running. But as in large steamers the funnels are 8 and even 10
feet in diameter a steam jet of 1½ inches would so to speak be lost in

page_text: the funnel and have so very little effect that its application would be
found nearly useless. Now in order to make this auxiliary blast pipe
practical in chimneys of steamers, and to meet the great difference of its
diameter in proportion to the diameter of the funnel I adopt the following
arrangement :-To the steam nozzle succeed several intermediate chim-
neys of different diameters superposed the onc above the other so that
the top chimney has the greatest diameter, and that they all form
intermediate nozzles between the steam nozzle and the funnel. Thus
the steam emanating from the steam nozzle will successively pass
through the superposed intermediate chimneys, aspirating or sucking on
cach passage from the one intermediate chimney to the next following
parts of the gases of combustion on their way from the boiler tubes to
the chimney, when at last passing the last intermediate chimney tho
steam will be mixed with a large quantity of gas, and although having
then a smaller velocity it will by the much increased mass and volume
act more effectually and assist more successfully the draught of the
chimney.
Another useful arrangement to assist the draught of the chimney
continually should a screw be found too complicated is to arrange the
aforesaid auxiliary blast pipe on a larger scale, and to actuate it instead
of by direct steam by atmospheric air blown through the nozzle (which
then would have a much larger diameter) by a good fan or blower.
Where there are many large chimneys in steam ships it may be useful
to dispose several blast pipes in the area of the chimney so that tho
increase of the draught instead of being produced by one steam jet or
jet of compressed air is produced by several,

page_text: year of our Lord One thousand eight hundred and seventy-four, in the
thirty-seventh year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Alexander Friedmann, Her
special licence that I, the said Alexander Friedmann, my executors,
administrators, and assigns, or such others as I, the said Alexander
Friedmann, my executors, administrators, 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 Islands, and Isle of Man, an
Invention for "IMPROVEMENTS IN HEATING STEAM BOILERS OF STEAM SHIPS,"
upon the condition (amongst others) that I, the said Alexander Fried-
mann, my executors or administrators, by an instrument in writing
under my, or their, or one of their hands and seals, should particularly
describe and ascertain the nature of the said Invention, and in what
manner the same was to be performed, and cause the same to be filed
in the Great Seal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, tho said Alexander Friedmann, do hereby
declare the nature of my said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement thereof, reference being had to the accom-
panying Drawings, that is to say :-
The consumption of fuel in steam ships is relatively very considerable
even when the engines are the most perfect that have hitherto been
designed. Up to the present time attention has been almost exclusively
paid to the engines; the construction of the boilers and their firing are
almost what they were originally.
The boilers of steam ships are actually still heated by means of fire-
grates, which receive for immediate combustion coal or other fuel. This
system of heating possesses, specially for steam ships, the greatest dis-
advantages, for not only is the combustion produced by means of the said.
grates incomplete, and the expenditure of fuel considerable, as in all fire-
grates, but also the special circumstances existing on steam ships increase
this consumption of fuel, and give rise besides to other great incon-
veniences which I will mention in order to enable the object of my
Invention to bo better understood.

page_text: On large steam ships there are from 20 to 30 or 40 fire-grates of 7 or
8 feet deep, and having a total surface of several hundred square feet.
As the layer of coal distributed over the grates should be very thin in
order to favor the combustion as much as possible the equal distribution
over so large a surface is a difficult and trying work. Besides, the
tenuity of the layer of fuel often gives rise to the formation of spaces,
through which much cold air enters, and this necessitates a frequent
repetition of the laborious chargings. The repeated openings of the
mouths of the furnaces allows a quantity of cold air to enter every time,
which cools the boiler without assisting the combustion, and causes a
suffocating heat to be thrown out upon the fireman. Again, at each
clearing of the grates the still incandescent cinders which fall through
and become extinguished are a further cause of unpleasantness. The
number of fire-places placed near each other in a narrow and confined
situation multiply these inconveniences, and it is thus that notwithstand-
ing the improvement of their engines steam ships consume more fuel than
locomotives for example, and that if we compare the service of the
fireman of a large locomotive having a power of more than 400 horses
with that of the dozens of firemen of a large steam ship we can under-
stand why it is only the less intelligent men who become firemen on
board steam ships, and that only for the shortest possible time. Even
with the best will in the tormenting conditions in which they are they
can only work imperfectly, and thus the consumption of fuel, which
largely depends upon the intelligence of the fireman, becomes from
purely technical and personal causes unfavorable in steam ships. It
would therefore be an important advance to introduce for the production
of steam in the boilers of steam ships an improvement in the heating
arrangements answering more favorably the technical and personal
conditions above explained.
It seems at first sight that one ought to introduce in ships heating by
gas the employment of which in metallurgy has been shewn to be so
advantageous that in works where this mode of heating has been properly
carried out the consumption of fuel has been reduced nearly 40 per cent.
In these works however the gas has been produced by means of Siemens'
generators, which are impracticable in vessels, because they require an
immense space, which would not be available in steam ships, and they
are besides provided with grates, the clearing of which is as laborious
and even more difficult than the ordinary grates of steam ships. In

page_text: the products of distillation of these layers, and escapes finally at h, h,
and into a gas conduit leading to the fire-box of the boiler situated
near the furnace. The consumption of coal near the tuyeres i, i,
develops a high temperature which causes the elements which are
not combustible but are rendered fusible by the addition to the coal
of lime or other like substances to run to the bottom in the state of
scoria, which are allowed to flow off from time to time by the opening m.
The high temperature exists only in the neighbourhood of the tuyeres
by the ascension of the hot gases resulting from the combustion and
their reduction into oxide of carbon, as also by the process of distillation
of the coal a considerable cooling is produced, by virtue of which the
gas arrives at the mouth with only a diminished temperature.
By the continued consumption of the layers near the tuyeres the
coal in the furnace descends successively from time to time, and a
fresh charge is supplied by the throat, care being taken to add previously
a suitable quantity of calcareous substances. The gases thus produced
in the furnace are conducted by a system of pipes to the fire-boxes
of the boilers, and reduced to complete combustion in any of the well-
known ways.
After the experience there has been in the working of blast furnaces
it is easy to find persons capable of conducting the work of a cylindrical
gas furnace, which is moreover much simplified here. For such a
furnace three men will be sufficient; two for carrying the coal and
charging the furnace, and the other for watching the blast, and from
time to time removing the scoriæ by the opening m.
The attention required by the boilers is naturally very simple, as
in all apparatus heated by gas, and one man will be sufficient for all
the boilers of a large vessel since he will have nothing to do but observe
the water level of the boilers, and according as one or another should
be stopped or put into work close or open the gas valves. The com-
bustion being complete the saving of coal will be considerable, and
smoke consumption perfect, as in all gas heating apparatus.
With this kind of heating the existing boilers can be made use of
at once without any necessity for altering them; but in the event of
fitting a new boiler or in constructing a new ship high-pressure boilers
can be employed of less volume, and as there is no fear with this system

page_text: that the cinders will obstruct the fire tubes they can be made narrow,
as in locomotives, and a quicker and more complete absorption of heat
be thus obtained.
The novelty of my Invention does not consist in the production of
gas by means of cylindrical furnaces because blast furnaces have been
in use for centuries, and for upwards of twenty years it has been the
practice to heat boilers with gases from blast furnaces; but the novelty
lies in the application and adaptation of these principles, and the employ-
ment of furnaces without fire-grates (and especially those constructed
as has been herein-before described) to and for the production of gas,
and the heating of boilers in steam ships.
It is necessary to think also of increasing the draft of the chimney
or funnel of steam ships, both for rendering the application of the gas
furnace more efficacious, and for obviating the inconveniences of the
existing modes of heating, which inconveniences are chiefly owing to
the weak natural draft of the chimneys of steam ships.
The most simple means of assisting the natural draft of the chimney
would be to establish a blast as in the chimneys of locomotives. But
such blast would produce here a less striking effect seeing that the
diameters of the chimneys of steam ships are much larger than those of
locomotives, and that a jet of steam emanating from a pipe of an inch
diameter would as it were be lost in a chimney of nearly 9 feet like those
of large ships. But in order to render this auxiliary means which is
so useful in locomotives practicable, also in steam ships I employ the
apparatus represented in Figures 2 and 3.
Figure 2 represents a vertical section, and Figure 3, a horizontal
section.
A is a steam pipe opening by a cock into the blast pipe T, the orifice
of which may be from one-fifth of an inch or less up to an inch and a
quarter, or even an inch and three-quarters or more in diameter,
according to the size of the chimney. This pipe is placed in the centre
of the chimney and preferably at the bottom thereof. The pipe T is
succeeded by superposed chimneys D³, D2, D3, D4, D³, of diameters
gradually increasing, and forming thus intermediate tubes between the
pipe T and the chimney in the space in which all these parts are
placed.

page_text: In order to put the apparatus in operation I open the valve of A, the
steam coming from the boiler escapes by T and enters the first
intermediate tube D', drawing therein and propelling a part of the gases
resulting from the heating of the boilers. The mixture of the steam and
of these gases escaping from D' enters D³, again drawing gases therein.
This process is repeated as far as the last intermediate tube D³ by which
there finally escapes a mixture of the initial steam arising from the
pipe T, and of a large quantity of gas successively accumulated. The
final speed with which this mixture issues from the last tube D³, and
enters the chimney is much less than the initial speed of the steam in T;
on the other hand the mass of this mixture is much greater and the
relation of the diameter of D³ to that of the chimney is no longer so
unfavorable as the relation of the diameter of the orifice of the blast
pipe; the effect on the mixture will therefore be much greater than if
the steam acted in this previous mixture. This arrangement therefore
renders practically useful in steam ships the blast pipes so long employed
in locomotives, and is of great value for steam ships no matter what may
be the system of heating their boilers. This mode of producing blast
might often be difficult to apply especially in ships with surface
condensers, seeing that the blast expands steam which cannot be
recovered for feeding the boilers, it will therefore be useful to be able to.
assist artificially the natural draft of the chimney in other ways. For
this purpose I fit in the chimney a screw like the screw of screw
steamers, in such manner that its shaft corresponds with the axis of the
chimney and extends beyond the bottom thereof, in order to be outside
it, well guided, and worked directly by a small horizontal steam engine.
When the engine is arranged so as to allow of working the screw of the
chimney, also by hand, the draft of the chimney can be assisted as soon
as the fire is lighted and before steam is got up.
The action of the screw is so well understood that its use as a drawer
and propeller of gas in a chimney and its construction require no
explanation, more especially as the novelty of my Invention both as
regards this screw, and the arrangement of blast above described consists
essentially in the adaptation or application of these means to the
chimneys of steam ships.
Anothin WARD
oful 154
of assisting the dunft of the shimun

page_text: 6. The fitting and use in the chimneys of steam ships of multiple
blast apparatus to assist the draft, substantially as herein-before
described.
In witness whereof, I, the said Alexander Friedmann, have here-
unto set my hand and seal, this Twenty-fifth day of July, One
thousand eight hundred and seventy-four.
ALEX. FRIEDMANN. (L.s.)