Improvements in and relating to Instantaneous Steam Generators.
Year: 1898

page_text: Date of Application, 25th Aug., 1898-Accepted, 25th Feb., 1899
COMPLETE SPECIFICATION.
Improvements in and relating to Instantaneous Steam Generators.
We, ALBERT VERBEKE, of 27, Rue de l'Est, Schaerbeck, Brussels, Electrician,
and OSCAR PIRSCH, of 320, Rue St. Gilles, Liége, Chemist, both in the Kingdom
of Belgium, 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 has for its object a novel form of generator for instantaneous
vaporization and for the burning of liquid fuel which constitutes a new applica-
tion of the well known phenomenon presented by water which when introduced
into highly heated capillary spaces vaporises instantaneously without passing
through the spheroidal state or the condition of calefaction. Generators con-
structed upon this principle are, generally speaking, formed of vaporising tubes
having thick walls and are of considerable weight, the object being to resist
deformation due to high pressures and the constitution of heat storage.
Owing to this fact, if for any reason such tubes become cold, too long a period
of time is required for the attainment of their normal temperature. From this
cause prejudicial diminutions in pressure arise.
In order to avoid this considerable weight of the tubes and to obviate the
necessity for the storage of heat and attain other advantages resulting from a
special method of heating, we have devised the arrangement hereinafter described
and represented in the accompanying drawings, in which;
Figure 1 is a longitudinal section of the generator as a whole.
Figure 2 is a vertical cross section of the same.
Figure 3 is a front elevation of the side upon which the steam collector is
arranged, and
Figure 4 is a sectional view, upon a larger scale, showing the method of joining
the tubes.
The generator is constituted by a number of cylindrical metallic tubes T, T₂ T
preferably of steel which form the essential part of the invention. These
tubes are deeply screw threaded upon their entire length, the width of the thread
being sufficient to impart to the tube great resistance to flexion.
The aim and effect of this screw threading is:
(1) To increase the heating surface to a large extent and consequently to
render the heating of the tubes more speedy.
(2) To impart to the tubes great resistance to fracture or deformation, the
thread being considered as a very strong binding or hooping which is certainly
stronger than hooping by means of ribs which method leaves the tube without
additional strength at those points at which there is no hooping.
(3) To permit of the use of lighter tubes which heat more readily and com-
municated their heat to the water passing through them, whilst at the same time
the strength of heavier tubes is secured.
These screw-threaded tubes are arranged within a metallic or other casing which
is internally lined with a bad heat conducting medium. They are so arranged
as to obtain the best results from the heat employed, that is to say they are in
ntimate contact with the gases from the furnace. An alternate or quincunx

page_text: arrangement of horizontal tubes is most advantageous. Under some conditions,
however, vertical or inclined tubes may be employed, or the tubes may be
arranged in any desired manner. The tubes are connected one with the other by
means of screw connections in the manner indicated in the drawing, or by any
other suitable means.
We prefer, however, to employ the screw connection represented at R Figures 1
and 4; the extremity of the screw-threaded tube is formed with a double bevel
or edge against which bears the collar of the connection. This collar is
formed of metal which is softer than the metal of which the screw-threaded tube
consists so that in tightening e the double bevel b slightly enters the softer
metal of the collar and forms a perfect joint without the use of any intermediate
substance such as asbestos copper and so forth.
This method of assemblage enables cleansing to be readily and rapidly effected.
because there is no need to consider the joints which are made automatically so
to speak. In the method of assembling the tubes which is represented in the
which is nearest
drawing, the feed water is injected into the row of tubes T,
to the furnace, and steam is taken from the upper tubes T-
Any other
arrangement may be adopted, it being remembered that the water should first
of all enter the tubes which are nearest the furnace.
.
In order to obviate calefaction in the screw threaded tubes we employ one of
the known processes, consisting in dividing the column of liquid into small
threads or strips by introducing into the tubes either a metallic gauze wound
upon itself or asbestos tissue or the like. The quantity of water contained by
the tubes under these conditions is extremely small and the vaporisation is very
rapid.
The thickness of the walls of the tubes may vary according to the uses to which
it is intended to put the boiler. If a very rapid heating of the tubes is desired
the walls of these latter are made extremely thin, which does not prevent any
disadvantage with pressures which are not too high, owing to the resistance
ensured by the screw threading. If on the other hand a strong apparatus is desire 1,
suitable for working at high pressures, tubes having thicker walls are selected,
care being taken, however, that the walls are not too thick in order that the
defects above referred to may not be produced.
A generator thus formed may be heated by ordinary combustible, such as
coal, coke and so forth, but in the greater number of cases we prefer to employ
liquid fuel such as ordinary lamp petroleum, purified petroleum, alcohol and
the like. In Belgium petroleum is especially suitable owing to its low price.
In order to obtain the maximum of heat by means of liquid fuel, it is necessary
to convert this latter into vapour and to burn it in a suitable apparatus in such
a manner as to produce a non-luminous blue flame.
For this purpose we prefer the arrangement illustrated in the drawing, more
especially in Figure 1, in two different constructional forms. In the first form
illustrated in the left hand portion of Figure 1, we cause a thin stream of
petroleum or other liquid fuel to enter through the tube t having very strong
walls and small internal section at a pressure from two to three atmospheres.
This liquid, which as we shall see is already vaporised, then enters a longitudinal
bar Bin which is formed a passage C for the whole of its length and which is
surmounted by flues cast in one with the bar or subsequently fixed thereto. At
the bottom of each flue or chimney is arranged a burner K whence issues the
combustible vapour and which is in communication with the passage C.
In order to start the apparatus, the tube and the bar B are heated to a tem-
perature exceeding slightly that of the point of ebullition of the combustible.
thereupon petroleum or other liquid fuel is introduced and becomes vaporised
in the tube issues through the burners K and burns above the flues. These
latter are merely provided at their lower portion with an air inlet A. There
is thus attained. by working under pressure a pale blue flame of very great
calorific value. The tube t is arranged in such a manner as to be situated in

page_text: direct contact with the flame issuing from the flues. In this manner the trans-
formation of petroleum into vapor is continual and the flues communicate owing
to conductibility to the bar B sufficient heat to prevent the condensation of the
petroleum vaporised in the tube t.
If it is desired to obtain a still more rapid vaporisation, the second construc-
tional form represented on the right hand of the drawing is employed. In
this form the bar B is replaced by a tube B₁ of the same section as the tube t
of which it may constitute a continuation. This tube is provided in the same
way with burners and flues which are fixed thereto in any manner which will
ensure intimate contact between them and the tube.
Having now particularly described and ascertained the nature of our said inven.
tion and in what manner the same is to be performed, we declare that what we
claim is:-
1. The novel form of generator for instantaneous vaporisation and for treating
by means of liquid fuel substantially as described above and represented in the
a whole, characterised essentially by a
accompanying drawing, considered as
system of tubes screw-threaded and a furnace adapted for the use of liquid fuel,
such as ordinary lamp petroleum, essences or the like.
2. In a generator for instantaneous vaporisation of the kind described in
Claim 1, the special arrangement of metal tubes provided externally with screw-
threading of some considerable depth the purpose and effect of which is to increase
the heating surface, to form a coiling or hooping protecting the tube against
deformation and to diminish the weight of the tubes whilst at the same time
ensuring their solidity.
3. In a generator for instantaneous vaporisation of the kind described in
Claim 1, the method of connecting the tubes illustrated in the drawing and
essentially characterised by an edge b entering to a slight extent the connecting
collar which is formed of softer metal than the screw-threaded tube, the joint
being formed automatically so to speak by tightening a nut e.
4. In a generator for instantaneous vaporisation, of the kind described in
Claim 1, the arrangement described above of a furnace for liquid fuel, character-
ised essentially by a series of burniers of the Bunsen type mounted upon a
perforated metal bar B or tube B₁ and supplied under pressure by means of
one or more pipes t in direct contact with the flames of the burners, substantially
as described and represented in the accompanying drawing.
101 law of
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicants.