Improvements in Instantaneous or Flash Steam Generators.
Year: 1898

page_text: Date of Application, 28th June, 1898
Complete Specification Left, 16th Mar., 1899-Accepted, 24th June, 1899
PROVISIONAL SPECIFICATION.
Improvements in Instantaneous or Flash Steam Generators.
I, ALPHONSE LAFARGUE, Mechanical Engineer, 55, Radipole Road, Fulham,
S.W., do hereby declare the nature of this invention to be as follows:-
This invention relates to that class of flash boilers where superheated steam is
generated instantaneously for propelling motor-car engines and secondly for
assisting the draught of furnaces or for other purposes. In effecting my improve-
ments I dispense with a water chamber outside the tubes, as in ordinary steam
boilers, in lieu of which I substitute highly heated metallic tubes, by which the
steam is generated instantaneously by the admission of a certain quantity of water
in the said tubes or retorts, and regulated by a pump driven from the engine
when in motion, or it may be an auxiliary pump or other contrivance.
The configuration or form given to the vaporising tubes is in the shape of a
laminated or restricted internal passage having fluted or corrugated surfaces so
as to bring the injected water into closer contact through the undulated heated
surfaces of the tubes thereby breaking and preventing "gulps" of water passing
through surrounded by steam and at the same time affording a greater amount
of heating surface externally and internally for evaporating purposes in limited
spaces.
The disposition of the tubes in generators may be so arranged as to meet the
various requirements most suitable either horizontally, obliquely, or vertically,
as may be most conducive for the exposure of the tubes to the flames inside the
furnace chamber.
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1000
Improvements in Instantaneous or Flash Steam Generators.
I, ALPHONSE LAFARGUE, of 55, Radipole Road, Fulham, in the County of
London, 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:-
―
This invention relates to that class of flash boilers in which the steam is
generated instantaneously, and has for its object to provide a generator whereby
superheated steam may be quickly and readily generated for the propulsion of
motor vehicles or for other purposes. The steam generator is of the water tube
[Price 801

page_text: type and the improvements have particular reference to the configuration and
arrangement of the tubes.
In carrying out this invention, the steam generator is built up of a series of
metallic tubes the configuration of which is such that they present a large heating
surface to the gases from the furnace, whilst an extensive surface is also presented
on the interior with which the water for conversion into steam is kept in close
contact. By this arrangement a large proportion of heat is absorbed from the
hot gases by the water tubes, from which again it is readily absorbed by the
water within them.
The configuration of the tubes and further details of the invention will be
clearly understood by reference to the accompanying drawings, in which
Figure 1 shows in perspective cross section one form of tube constructed
according to this invention.
Figure 2 is a similar view of a modified form of water tube,
Figure 3 is a similar view of another modification of the same,
Figure 4 is an end elevation of one of the elements of the steam generator
provided with tubes of the configuration shown in Figure 1,
Figure 5 is a side elevation of Figure 4, and
Figure 6 is an end view of a generator illustrating one method of arranging
the clements in the same.
The water tube shown in Figure 1 is flattened in form, having a bore of
elongated cross section, and the interior and exterior of the tube is longitudinally
corrugated or undulated. The external corrugations thus present a large surface
to the hot gases which surround the tubes when in place in the generator, and
the internal corrugations or undulations present a large water surface
and tend to break up the flow of the water through the tubes thus preventing
small bodies of water surrounded by steam from passing through the tube without
coming into contact with the heated sides of the same. This is also further
prevented by the narrowness of the bore in one direction.
The modified configuration of tube shown in Figure 2 is a further develop-
ment of the principle illustrated by the construction of tube described with
reference to Figure 1, the cross section of the tube being still elongated, the
longitudinal corrugations being however more pronounced. The corrugations
shown in Figure 2 are angular, whilst those shown in Figure 1 are curved. This
form of tube may be preferred as presenting a still greater heating surface than
that illustrated in Figure 1.
In Figure 3 the walls of the tube are shown to be somewhat thicker than in
either of the figures already referred to, and the corrugations are not quite so
pronounced.
The tubes A may be arranged adjacent to each other in squared ends such as B
to form elements as shown in Figures 4 and 5. By this arrangement a great
number of tubes may be compactly arranged with only a small space between
each pair of tubes, so that the hot gases surrounding the tubes are broken up
into a number of small streams, each of which is brought into contact with and
imparts its heat to the corrugated surfaces of the tubes. By this means no large
body of gas can pass between the tubes and escape into the atmosphere without
imparting the greater proportion of its heat to the water tubes.
Moreover the tubes are arranged edgewise to the general direction of flow of
the hot gases, and, being flattened as described can be so placed that although
closely spaced there is nevertheless a clear passage-way for gas between each pair:
this passage-way moreover enables the outside surfaces of the tubes in each
element to be readily accessible for cleaning. Further as all the waterways are
straight a cleaning rod can very easily be passed down the interior of the tubes
to keep them clean.
The disposition of the tubes in the generator may be arranged as preferred to
meet various requirements, that is they may be arranged horizontally, obliquely
or vertically, so as to present as large a portion as possible of the tubes to the

page_text: flames or hot gases from the furnace chamber, and water may be fed to the
generator by any known form of injector or pump operated by power or by hand.
A convenient arrangement of tubes is illustrated in Figure 6. The elements
which may lie in either a horizontal or inclined plane are by means of their
square ends B placed side by side in such a manner that the spaces between
the tubes A in one row of elements are at right angles to the spaces between the
tubes A of the row of elements above them, so that the hot gases rising from the
furnace C pass through the spaces between the tubes A in the bottom row of
elements but are checked by the second row in which the broad sides of the
tubes A face the spaces through which the gases have passed and thus the current
of gases is broken up and made to filter its way among each series of tubes until
it passes through the uppermost row of elements and is carried away by down
flues D. By breaking up the current of the gases and by retaining them thus
among the tubes much greater opportunity is afforded for the absorption of heat
by the tubes A than if the gases were allowed free passage between them. The
square ends B of the elements permit various arrangements of this nature and
in order to still further complicate the passage of the gases the tubes A may
if desired be set obliquely in the square ends 13, that is the flat sides of the
tubes need not be parallel to either of the sides of the square ends. The different
elements may be connected together in any well known manner.
It will be understood that though particularly suited to the propulsion of motor
vehicles, this steam generator may be used for any other purpose, such as supply-
ing motive power for stationary engines. Or the tubes or generator could he
employed in the generation of vapour or steam from liquids other than water.
Moreover, they could be used in condensers.
Having now particularly described and ascertained the nature of my said in-
vention and in what manner the same is to be performed I declare that what I
claim is
-
1. In a steam generator a flat tube which for the purpose described is longi-
tudinally corrugated and has an elongated cross section substantially such as is
illustrated in Figure 1, or Figure 2 or Figure 3 of the accompanying drawings.
2. In a steam generator an element in which tubes of the kind described are
arranged adjacent to each other in the manner illustrated in Figure 4 of the
accompanying drawings for the purpose specified.
3. In a steam generator elements grouped in the manner described and com-
prising tubes of the kind specified.
4. The water tube constructed substantially as described or illustrated in
Figure 1 or Figure 2 or Figure 3 of the accompanying drawings,
Dated this 14th day of March 1899.
ALPHONSE LAFARGUE.
Boult & Wade,
Agents for the Applicant.