Improvements in Apparatus for Generating Steam or Vaporizing Liquids.
Year: 1890

page_text: Date of Application, 8th Aug., 1890
Complete Specification Left, 15th Apr., 1891-Accepted, 16th May, 1891
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Generating Steam or Vaporizing
Liquids.
I, DANIEL BETHMONT of 1 Boulevard St. Denis, Paris, France, Manufacturer,
do hereby declare the nature of this invention to be as follows:-
Various objections have been raised to the steam generators which have a capillary
vaporizing space and are known by the name of instantaneous vaporizing generators.
These objections have reference more particularly to the following points :-
The so-called instantaneous vaporization is only obtained with the aid of large
grate surfaces which consume more fuel than is useful in proportion to the heating
surface. Under these conditions the expense is too great for the result obtained.
On the other hand the capillarity of the vaporizing space, a capillarity which
constitutes the characteristic and essential feature of the system, really only exists
when the generator has not been put in contact with the flame.
Most of these generators are constructed of several metals connected together,-
wrought iron, steel or copper, that is to say metals which dilate considerably.
As soon as one of these generators is put to work the outer metals dilate more
than the inner metals and destroy the capillarity of the vaporizing space, which
widens considerably and attains even a centimetre in width, or more, according
as the fire is more or less violent or the draught is more or less powerful
When the generator is formed of a single metal or alloy the capillary space being
then obtained by an oblong passage in the form of a thin slit, this metal or alloy
becomes distorted under the simultaneous influences of the internal pressure and of the
temperature. The slit widens every time that the state defined by a given tempera-
ture and a given pressure allows the metal to exceed its limit of clasticity. The
generator instead of having a capillary space therefore becomes an ordinary generator.
Under these conditions the working is very dangerous, more dangerous than with
ordinary boilers, because the generator is supposed to contain only unimportant
quantities of water and steam, while in fact there is a boiler of ordinary capacity
without safety appliances.
When
Another serious cause of accident is due to the chemical disaggregation of the
metals hitherto employed for the construction of these generators.
wrought iron or steel is employed these metals oxidize very rapidly on the exterior:
the oxide formed becomes detached and the generator tubes diminish in thickness.
In the interior of the generator tubes the matter is still worse; the tube being
heated to redness either by the action of a badly regulated fire or during stoppages,
the water which is injected into the vaporizing space becomes immediately
decomposed and produces magnetic oxide in large flakes which accumulate at the
orifices of the tube or pass into the parts of the engine worked by the generator.
The results are, stopping up of the apparatus, deterioration of the engine, con-
siderable increase of pressure and of feed, rapid destruction of the generator, and
if the apparatus is not frequently changed, accidents will occur. When the
generator is constructed entirely of copper magnetic oxide is not produced, but
with this metal a large quantity of scales of calamine is formed which very rapidly
cause deterioration of the generator; besides the tube becomes very quickly
distorted under the action of the high temperature and of the high pressure.
Lastly, as I have above stated, when wrought iron, steel or cast iron are
employed simultaneously with copper, the differences of dilatation of the metals
very quickly lead to ruptures.
With the object of avoiding these various objections I have designed a new
system of very rapid vaporizing generators without capillary spaces, but having

page_text: a very restricted vaporizing space, which is always the same, always positive and
certain and is not liable to become stopped up or deteriorated or become
distorted. This new system. of steam generator or liquid vaporizer forms the
subject of the present invention which can obviously be carried out in various
ways.
According to one arrangement of my new kind of generator of very restricted
but non-capillary vaporizing space, I employ a single metal, cast iron, which owing
to the arrangement of the inner non-capillary vaporizing space will not become
distorted; it will be cheap and overcome all dangers or causes of accident by the
very small and definite quantity of water contained therein, by the relative
smallness of the grate surface and by the addition of regulating apparatus or
automatic safety appliances. This generator is composed of a plate or block with
cylindrical holes formed therein during the casting, these holes constituting external
tubes. In each of these holes or tubes I place a cast iron rod, core or mandril
having cast thereon a screw projecting about two and a half millimetres to constitute
with the outer tube an inner non-capillary vaporizing space. The tubes commu-
nicate with each other in pairs in a chamber closed opposite each tube by caps or
covers which allow of the withdrawal of the rods.
In another generator of the same kind the communicating chamber is closed
by means of plugs and inner plugs; these plugs are screwed into the cast iron
and for greater safety the outer plugs are hammered externally when in place.
In another modification the generator is likewise formed of a cast iron plate but
has a groove of serpentine or other form to receive a rectangular or flat copper tube
forming the inner non-capillary vaporizing space; this tube is composed of two parts
placed against each other one of them being concave; it is covered with a thin
metal strip, then a layer of cast iron is run upon the top. The interposition of the
metal strip which can be connected by a wire to ensure its position facilitates the
union of the copper and cast iron while preventing the tube melting, and the covering
of this with a thin sheet of tin facilitates the cohesion of the metals, consequently the
effects of dilatation become unimportant.
Instead of the groove containing a copper tube as just described it may itself
constitute the non-capillary vaporizing space or chamber, or the groove may be
fitted with a round or oval copper tube with a rod or core forming the non-capillary
vaporizing space or chamber by means of a helicoidal groove; or the copper tube
may be formed of a plate bent into U-form, or be a flattened copper tube to form
the vaporizing chamber.
In all cases where the groove is fitted with a copper tube the non-curved parts
of this groove can have rises and falls to distribute the differences of dilatation in
the angles.
In another modification of my generator an outer tube has a copper lining of
considerable thickness which preserves it from oxidation and bears the strain of
the pressure.
A core or rod forms with this lining the non-capillary vaporizing
chamber with the aid of a helicoidal groove. The lining can be formed of a rolled
copper plate over the joint of which I can apply a metal strip to prevent contact of
the water with the cast iron or other metal constituting the outer tube. The strip
can in some cases be advantageously replaced by two or more concentric linings
having their joints at diametrically opposite points. I can also with the same
general idea cover the inside of a material which will resist high pressures and
temperatures with another material having the single function of preventing more
or less the contact of the vapor with the easily oxidizable material. For example
a steel tube can be surrounded with cast iron or cast steel and lined with a
copper tube which is completely free to dilate or is retained by a collar at
one end.
For purposes in which cast iron would be considered sufficiently proof against
oxidation but would have the effect of want of security as regards strength
I arrange in the interior of the cast iron mass a resisting tube of wrought iron
or steel and either plain or perforated. Or this tube forming a skeleton or

page_text: framework of resistance embedded in the wall of the generator can be in other
forms such as a wound band or wires of iron or steel.
It is a novel feature to subdivide in a generator the nature of the metals
employed, so as to allot to each of them the part for which it is adapted. It is
thus that in the arrangements that I have described it will be observed that
there is a tendency to employ: First, copper, German silver or even cast iron
alone or mixed with aluminium or nickel as raporizing chambers, these metals
being the least liable to oxidation and their oxides not forming flakes or matters
which are liable to cause obstructions; Second, steel or wrought iron as a body
of resistance preventing the generators in case of rupture from becoming detached
in pieces or fragments; Third, cast iron or steel alone or alloyed with other
metals as a reserve of caloric and as a heating surface, in contact with the gases,
this employment of cast metals making it very easy to construct arrangements for
the absorption of caloric by means of gills and partitions with which the gases
come in contact.
The combinations of different natures of metals in accordance with the spirit
which I have above explained has the double object of ensuring their technical
success by their good action, by their great durability and by the permanence of
the vaporizing space, the small cost price and the economy of the materials employed
and a great reduction in hand labor.
In another modification of my generator a cast iron tube of cupola form is lined
with copper; a bronze mandril or core forms the non-capillary space or chamber
with the aid of a helicoidal groove and the steam escapes by a longitudinal hole in
the mandril. This will be cast with a core which remains permanently therein.
If this core were not left it would necessitate an air hole from the cavity of the
mandril to its outer end.
In another modification the outer tube is of copper it may or may not have
gills and it is embedded in a cast iron sheath with or without gills. The inner tube
is of cast iron with or without gills according to whether it is required or not to
have a return passage for the gases, and it comprises a helicoidal groove to form
the non-capillary vaporizing space. A jacket of brass, German silver or other
metal can be used to preserve it from oxidation if the cast iron should not be
sufficiently proof against oxidation by superheated steam.
In another modification the vaporizing space or chamber is of waved form. It
is composed of two concentric cast iron tubes; the outer tube has gills for increasing
the heating surface and instead of the inner tube a mandril can be employed;
a non-oxidizing metal lining can be applied to each of these tubes.
In another modification the two tubes are of cast iron the outer tube having
gills and the inner tube a helicoidal groove to form a non-capillary vaporizing space.
The inner tube can be cast with a core which remains therein or a solid mandril
can be used instead.
I can also construct generator tubes of one or two strips of metal drawn, rolled
or arched, then covered with thin strips of metal which are wound thereon to a
sufficient thickness to produce a solid tube, strong enough to resist the required
pressure. The tube may for example he formed of two strips placed against each
other, one of them being of concave form; or the tube may be formed of a
single strip the meeting edges of which may be at any suitable place, either at the
ends or sides.
In another modification of my generator the non-capillary vaporizing space
comprised between an outer tube and a mandril is ensured by means of studs or
projections fixed to or cast with the mandril.
In another modification which may be of oval form the non-capillary vaporizing
space is ensured by means of a wire wound helically around the inandril; in order
that this winding may be regular the mandril is formed with grooves in which the
wire engages.
In cases where I have employed flattened tubes I have observed that as a rule
the tube is liable to open in the vicinity of the small sides of the rectangle; this

page_text: points to an exaggerated wear or strain of the metal at these parts. In order to
obviate this I construct flattened tubes with their small sides strengthened and so
that they become what I may call "flattened tubes of equal resistance." They
may be made in various ways, either cold or hot. They may be flattened between
rolls with the interposition of a mandril, the rolls having the effect not only of
flattening the tube but also of diminishing the thickness of the long sides of the
rectangle according as this operation is performed by cylindrical or arched rolls
or even by means of a draw plate the forms of tube obtained will be more or less
oval and more or less of equal resistance. Another way of making these tubes
consists in drawing or forming cylindrical tubes with two wings and then simply
flattening them or reducing the thickness of the long sides of the rectangle either
simultaneously with or after the flattening.
It is important for a generator composed of cast iron as an equalizer or store of
heat and of a flattened copper or German silver tube, that the different parts of this
tube shall preserve full liberty to dilate while being firmly protected against
distention. I can effect this by forming the generator element of four (or other
number of parallel branches or turns of copper tube carefully embedded for its
whole length. In the parts where the round section becomes changed into a
flat section the tube is supported on cast iron pieces which scrupulously follow
all the forms of the copper tube. These cast iron pieces are connected to the
generator element by means of dowels forming guides or slides. It is the same
with a piece which supports the central bend of the tube. It will be understood
that these cast iron pieces being fixed to the tube and the spaces between the
piece forming the body of the generator element, and the cast iron pieces being
nil at the temperature of the atmosphere, all these pieces will have relative move-
ments during work due to the effects of dilatation. The dowels will therefore have
the duty of preserving the copper tube from all strain which might arise from the
weight of the cast iron pieces at the parts where it ceases to be supported after
the movement or separation of the small cast iron pieces from the body of the
generator element.
In another modification of generator element the liquid to be vaporized enters
an annular space having for the whole or part of its length a single or multiple
helicoidal passage and a section more or less great, constant or variable, and a
pitch likewise constant or variable. The exterior of the screw or helix may or
may not be in contact with the tube constituting the vaporizing space. The ends
of this vaporizing space are of novel construction. They are composed of a ring
in two pieces partly embedded in the outer tube and of a flange or part to receive
the other part of this ring; also of a junction piece with an annular recess to
receive the end of the outer tube, a suitable material being interposed to form a
joint. These joints leave the tubes at full liberty to dilate. The outer tube
forming the vaporizing space is of steel, cast iron or other resisting metal. The
mandril or inner rod is of cast iron, cast brass or other metal which is cheap and
more or less proof against oxidation and the products of oxidation of which are
casily driven out. The junction box, the joint of which is arranged like that above
described has this peculiarity, that the steam passage immediately beyond the outlet
from the generator element, and before re-entering the next element has one or
more enlargements constituting receptacles for foreign matters drawn by the steam,
such for example as those arising from deposits or incrustations, or from the
oxidation of the metals. Purge cocks attached to the enlargements or other
suitable devices may be employed to drive out these matters even while the generator
is at work.
Another modification of generator element differs from that last described in the
constitution of the vaporizing chamber. It is composed of a copper tube and of
an outer jacket in the form of a steel tube more or less thick; the copper having
the property of not oxidizing in large flakes is specially adapted for purposes where
it is desired to communicate the heat which it receives very rapidly to the fluid.
The employment of steel for the jacket is because of its great strength even for

page_text: very high temperatures, its very high melting point and its great resistance to
chemical and physical actions of all natures. The core or mandril has longitudinal
ribs, the effect of which is to centre, or approximately centre, or even if desired to
throw out of the centre to a certain extent, the core relatively to the vaporizing
chamber; these ribs have the further object of facilitating the expulsion of foreign
matters which would form an obstacle to the current of steam in the vaporizing
space or chamber by giving to this mandril mechanically and externally a rotary
or longitudinal movement or a combination of longitudinal and rotary movements
which movements may be continuous or intermittent, and automatic or not.
Another form of generator element has the peculiarity that its core is without a
screw and has simply at the two ends or at one or more points of its length a series
of projections to centre or approximately centre it in its place. In another element
the metal forming the jacket is cast around a tube of steel forming a resisting body
in which is lodged the copper tube containing the fluid. The mandril has a
conical body with a helix thereon.
The last portions of a generator have special need for a mandril with a helix
thereon, because the rotary movement imparted to the fluid will, on account of the
centrifugal force, throw against the heated sides all the small drops which are drawn
by the fluid, but this arrangement is not absolutely necessary.
I can employ for the feed of the liquid an apparatus for reducing it to spray so
as to further hasten the vaporization.
I can also employ in the same generator, elements of different construction and
joints or connections of different forms according to the position and the conditions
in which the generator has to be employed. The cores or mandrils themselves may
be of different forms; they may be entirely smooth or smooth at one part of their
length and have a helix or ribs of various forms at other parts of their length. The
vaporizing channels or chambers formed by these ribs may be conical so as to
facilitate the expulsion of the obstacles towards the wider sections.
As I have already stated a generator can be formed of generator elements of
various kinds. One part of the generator may be formed of separate detached
tubes, another part be composed of jacketted tubes connected by several tubes or
plates, and these plates may form partitions for directing the products of
combustion &c.
In one modification of my invention the vaporizing tubes are closed by double
boxes held by a single bolt and allowing of the mandrils or cores being withdrawn
for cleaning these mandrils have a progressive helix; they are conical so that the
space between the tube and the base of the helix increases to give a larger passage
to the steam in proportion to the increase of its temperature.
In other modifications there are mandrils, or cores with helices or longitudinal
ribs having continuous or interrupted striations which constitute stops for the water
and cause it to follow the helices or the longitudinal ribs.
Or the mandril or core may have a broken or interrupted helix so as to form a
kind of chamber for the deposit of calcareous matters and facilitate the rupture or
breaking up of these calcareous deposits and the cleansing of the tubes.
Or the mandril or core may be without a helix but have projections in greater
or less number of various forms and dimensions and placed either longitudinally or
transversely in relation to the axis of the core.
Dated this 8th day of August. 1890.
J. C. MEWBURN,
55 & 56, Chancery Lane, London, Patent Agent.

page_text: COMPLETE SPECIFICATION.
Improvements in Apparatus for Generating Steam or Vaporizing
Liquids.
I, DANIEL BETHMONT of 1 Boulevard St. Denis, Paris, France, Manufacturer,
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:-
Various objections have been raised to steam generators which have a capillary
vaporizing space and are known by the name of instantaneous vaporizing generators.
These objections have reference more particularly to the following points."
The so-called instantaneous vaporization is only obtained with the aid of large
grate surfaces which consurne more fuel than is useful in proportion to the heating
surface. Under these conditions the expense is too great for the result obtained.
On the other hand the capillarity of the vaporizing space, a capillarity which
constitutes the characteristic and essential feature of the system, really only exists
when the generator has not been put in contact with the flame.
Most of these generators are constructed of several metals connected together,
wrought iron, steel or copper, that is to say, metals which dilate considerably. As
soon as one of these generators is put to work, the outer metals dilate more than
the inner metals and destroy the capillarity of the vaporizing space which widens
considerably and attains even a centimetre in width or more, according as the fire
is more or less violent, or the draught is more or less powerful.
When the generator is formed of a single metal or alloy, the capillary space being
then obtained by an oblong passage in the form of a thin slit, this metal or alloy
becomes distorted under the simultaneous influences of the internal pressure and of
the temperature. The slit widens every time that the state defined by a given
temperature and a given pressure allows the metal to exceed its limit of elasticity.
The generator instead of having a capillary space therefore becomes an ordinary
generator. Under these conditions the working is very dangerous, more dangerous
than with ordinary boilers, because the generator is supposed to contain only
unimportant quantities of water and steam, while in fact there is a boiler of ordinary
capacity without safety appliances.
Another serious cause of accident is due to the chemical disaggregation of the
metals hitherto employed for the construction of these generators.
When wrought iron or steel is employed these metals oxidize very rapidly on the
exterior, the oxide formed becomes detached and the generator tubes diminish in
thickness. In the interior of the generator tubes the matter is still worse; the tube
being heated to redness either by the action of a badly regulated fire or during
stoppages, the water which is injected into the vaporizing space becomes
immediately decomposed and produces magnetic oxide in large flakes which
accumulate at the orifices of the tube, or pass into the parts of the engine worked
by the generator. The results are, stopping up of the apparatus, deterioration of
the engine, considerable increase of pressure and of feed, rapid destruction of the
generator, and, if the apparatus is not frequently changed, accidents will occur.
When the generator is constructed entirely of copper magnetic oxide is not
produced, but with this metal a large quantity of scales of calamine is formed which
very rapidly causes deterioration of the generator; besides the tube becomes
very quickly distorted under the action of the high temperature and of the high
pressure.
Lastly, as I have above stated, when wrought iron, steel or cast iron are employed
simultaneously with copper the differences of dilatation of the metals very quickly
lead to ruptures.
With the object of avoiding these various objections I have designed a new
system of very rapid vaporizing generators without capillary spaces but having a
very restricted vaporizing space which is always the same, always positive and

page_text: certain and is not liable to become stopped up or deteriorated or become
distorted. This new system of steam generator or liquid vaporizer forms the
Bubject of the present invention which can obviously be carried out in various ways
and will be fully understood on reference to the annexed drawings and the following
explanations.
Figures 1, 2, and 3 represent respectively a sectional elevation, a sectional plan
and a transverse section of one arrangement of my new kind of generator of very
restricted but non-capillary vaporizing space. In this arrangement employ a
single metal, cast-iron, which owing to the arrangement of the inner non-capillary
vaporizing space, will not become distorted, it will be cheap and overcome all
dangers or causes of accident by the very small and definite quantity of water
contained therein, by the relative sinallness of the grate surface and by the addition
of regulating apparatus or automatic safety appliances. This generator is
composed of a plate or block a with cylindrical holes formed therein during
the casting, these holes constituting external tubes. In each of these holes or tubes
I place a cast iron rod, core or mandrel e, having cast thereon a screw d projecting
about 2 millimetres to constitute with the outer tube an inner non-capillary
vaporizing space. The tubes communicate with each other in pairs in a chamber f
closed opposite each tube by caps or covers which allow of the withdrawal of
the rods.
In another generator of the same kind, represented in Figures 4, 5, and 6, the
communicating chambers are closed by means of plugs hand inner plugs i; these
plugs are screwed into the cast iron, and for greater safety the outer plugs are
hammered externally when in place. In another modification illustrated in Figures 7
and 8, the generator is likewise formed of a cast iron plate a but has a groove of
serpentine (or other) form to receive a rectangular or flat copper tube forming the
inner non-capillary vaporizing space; this tube is composed of two parts placed
against each other, one of them being concave; it is covered with a thin metal
strip, then a layer of cast iron is run upon the top. The interposition of the
metal strips, which can be connected by a wire to ensure their position, facilitates
the union of the copper and cast iron while preventing the tube melting, and the
covering of this with a thin sheet of tin facilitates the cohesion of the metals,
consequently the effects of dilatation become unimportant.
Figure 9 illustrates different modifications which can be made in the manufacture
of this generator. In the first of these the groove does not contain a copper tube
but itself constitutes the non-capillary vaporizing space or chamber. The second
arrangement is that shown in Figures 7 and 8. The third arrangement shows the
groove fitted with a round or oval copper tube with a rod or core forming the non-
capillary vaporizing space or chamber by means of a helicoidal groove in the
fourth case the copper tube is formed of a plate bent into U-form, and in the fifth
case a flattened copper tube forms the vaporizing chamber.
In all cases where the groove is fitted with a copper tube the non curved parts of
this groove can have rises and falls, as shown in Figure 10, so as to distribute the
differences of dilatation in the angles a a¹ a² a³.
Figures 11, 12 and 13 represent an arrangement of my generator in which the
outer tube a has a copper lining of considerable thickness which preserves it from
oxidation and bears the strain of the pressure. The core or rod c forms with this
lining the non-capillary vaporizing chamber with the aid of a helicoidal groove.
As shown in Figures 12 and 13 the lining is formed of a rolled copper plate over
the joint of which I can apply a strip d to prevent contact of the water with the
cast iron or other metal constituting the tube a. The strip d can in some cases be
advantageously replaced by two or more concentric linings as shown in Figure 13b
having their joints at diametrically opposite points. I can also with the same
general idea cover the inside of a material which will resist high pressure and
temperatures with another material having the single function of preventing more
or less the contact of the vapor with the easily oxidizable material. For example
in Figure 13er have represented a steel tube a surrounded with cast iron or cast

page_text: steel and lined with a copper tube & which is completely free to dilate or is retained
by a collar at one end.
For purposes in which cast iron would be considered sufficiently proof against
oxidation but would have the effect of want of security as regards strength,
arrange in the interior of the cast iron mass a resisting tube m Figure 139ater of
wrought iron or steel and either plain or perforated. Or this tube forming a
skeleton or framework of resistance embedded in the wall of the generator can be
in other forms such as a wound band or wires of iron or steel.
It is a novel feature to subdivide in a generator the metals of different nature
employed so as to allot to each of them the part for which it is adapted. It is thus
that in the arrangements that I have described it will be observed that there is a
tendency to employ first, copper, German silver or even cast iron alone or mixed
with aluminium or nickel as vaporizing chambers, these metals being the least
liable to oxidation and their oxides not forming flakes or matters which are liable
to cause obstructions: Second; steel or wrought iron as a body of resistance
preventing the generators in case of rupture from becoming detached in pieces or
fragments; Third; cast iron or steel alone or alloyed with other metals as a reserve
of caloric and as a heating surface in contact with the gases, this employment of
cast metals making it very easy to construct arrangements for the absorption of
caloric by means of gills and partitions with which the gases come in contact.
The combinations of metals of different natures in accordance with the spirit which
I have above explained have the double object of ensuring their technical success
by their good action, by their great durability and by the permanence of the
vaporizing space, the small cost price and the economy of the materials employed
and a great reduction in hand labor.
The generator represented in Figures 14 and 15 is formed of a cast iron tube a
of cupola form lined with copper b; a bronze mandrel or core c forms the non-
capillary space or chamber with the aid of a helicoidal groove, and the steam
escapes by a longitudinal hole in the mandrel c. This will be cast with a core
which remains permanently therein. If this core were not left it would necessitate
an air hole from the cavity of the mandrel to its outer end.
Figures 16 and 17 show an arrangement in which the outer tube a is of copper;
it may or may not have gills and it is embedded in a cast iron sheath b with or
without gills. The inner tube e is of cast iron with or without gills according to
whether it is required or not to have a return passage for the gases and it comprises
a helicoidal groove to form the non-capillary vaporizing space. A jacket of
brass, German silver, or other metal can be used to preserve it from oxidation
if the cast iron should not be sufficiently proof against oxidation by superheated
steam.
Figure 18 shows an arrangement in which the vaporizing space or chamber is of
waved form. It is composed of two concentric cast iron tubes; the outer tube a
has gills for increasing the heating surface and instead of the inner tube ba
mandrel can be employed; a non oxidizing metal lining can be applied to each of
these tubes.
In Figures 19 and 20 the two tubes are of cast iron, the outer tube a having gills
and the inner tube a helicoidal groove to form a non-capillary vaporizing space.
The inner tube can be cast with a core c which remains therein or a solid mandrel
can be used instead.
Figures 21 to 26 represent tubes constructed in the following manner. They are
formed of one or two strips of metal a drawn, rolled or arched, then covered with
thin strips of metal which are wound thereon to a sufficient thickness to produce
a solid tube strong enough to resist the required pressure. In Figure 23 the tube
is formed of two strips placed against each other, one of them being of concave
form and in the other figures it is formed of a single strip the meeting edges of
which may be at any suitable place, either at the ends or sides, these tubes are
adapted for employment in the arrangement described with reference to Figures 7
and 8.

page_text: Figures 27 and 28 represent an arrangement of my generator in which the non
capillary vaporizing space comprised between the outer tube a and the mandrel 6 is
ensured by means of studs or projections c fixed to or cast with the mandrel.
In Figures 29, 30 and 31 which represent a generator of oval form the non-
capillary vaporizing space is ensured by means of a wire wound helically around the
mandrel in order that this winding may be regular the mandrel is formed with
grooves in which the wire engages.
In cases where I have employed flattened tubes I have observed that as a rule
the tube is liable to open in the vicinity of the small sides of the rectangle; this
indicates increased wear or strain of the metal at these parts. In order to obviate
this I construct flattened tubes with their small sides strengthened and so that they
become what I may call "flattened tubes of equal resistance." Figure 32 represents
several forms of these tubes in section. They may be made in various ways either
cold or hot. They may be flattened between rolls with the interposition of a
mandrel, the rolls having the effect not only of flattening the tube but also of
diminishing the thickness of the long sides of the rectangle. According as this
operation is performed by cylindrical or arched rolls or even by means of a draw
plate the forms of tube obtained will be more or less oval and more or less of equal
resistance, see Figure 32. Another way of making these tubes consists in drawing
or forming cylindrical tubes with two wings as shown in Figure 33 and then simply
flattening them or reducing the thickness of the long sides of the rectangle either
simultaneously with or after the flattening.
It is important for a generator composed of cast iron as an equalizer or store of
heat and of a flattened copper or German silver tube, that the different parts of this
tube shall preserve full liberty to dilate while being firmly protected against
distension. Figures 34 and 35 will explain how 1 effect this. The generator
clement is composed of four parallel branches or turns of copper tube carefully
embedded for its whole length. In the parts where the round section becomes
changed into a flat section that is at a and the tube is supported by cast iron
pieces p which scrupulously follow all the forms of the copper tube. These cast iron
pieces are connected to the generator element by means of dowels e forming guides
or slides. It is the same with the piece d which supports the central bend of the
tube. It will be understood that the cast iron pieces pp, d and e being fixed to the
tube, and the spaces between the piece e on the one hand and the pieces p p and d
on the other being nil at the temperature of the atmosphere, all these pieces will
have relative movements during work due to the effects of dilatation. The dowels c
will therefore have the duty of preserving the copper tube from all strain which
might arise from the weight of the cast iron pieces at the parts where it ceases to be
supported after the movement or separation of the small cast iron pieces from the
body of the generator element.
The various tubes shown in Figures 1 to 26 and already referred to can be
produced in all desired forms and sizes; their style of construction requires only a
cheap material. I can apply them to all purposes and particularly to generators
with restricted and so-called capillary vaporizing spaces, and especially in the
employment of cast, rolled or stamped plates. I can also form them of various
metals or alloys such as German silver, nickel, ferro-nickel, &c., these metals, nickel
particularly, having a greater strength than copper, and less dilatation.
Figures 36, 37 and 38 represent various generator elements which I can employ
either separately or grouped or in combination with each other, according to special
conditions or requirements. Figure 36 represents an element which is supposed to
receive at a the liquid to be vaporized; this liquid enters an annular space having
for the whole or part of its length a single or multiple helicoidal passage and a
section which can be more or less great, constant or variable, and a pitch which can
likewise be constant or variable. The exterior of the screw or helix may or may
not be in contact with the tube constituting the vaporizing space. The ends of this
vaporizing space are of novel construction. They are composed of a ring b in two
pieces partly embedded in the tube c and of a flange or part d to receive the other
BB

page_text: part of this ring also of a junction piece with an annular recess e to receive the
end of the tube e, a suitable material being interposed to form a joint. These
joints leave the tubes at full liberty to dilate. The tube c forming the vaporizing
space is of steel, cast iron or other resisting metal. The mandrel or inner rod is of
cast iron, cast brass or other metal which is cheap and more or less proof against
oxidation and the products of oxidation of which are easily driven out.
The
junction box the joint of which is arranged like that above described has this
peculiarity, that the steam passage immediately beyond the outlet from the
generator element and before re-entering the next clement has one or more enlarge-
ments yg constituting receptacles for foreign matters drawn by the steam, such
for example as those arising from deposits or incrustations or from the oxidation
of the metals. Purge cocks attached to the enlargements 9 and or other
suitable devices may be employed to drive out these matters even while the generator
is at work.
The generator element shown in Figure 37 differs from that last described
first in the constitution of the vaporizing chamber. It is composed of a copper
tube and of an outer jacket in the form of a steel tube more or less thick;
the copper having the property of not oxidizing in large flakes is specially
adapted for purposes where it is desired to communicate the heat which it
receives very rapidly to the fluid. The employment of steel for the jacket is
because of its great strength even for very high temperatures, its very high
melting point and its great resistance to chemical and physical actions of all
natures. The core or mandrel is supposed to have longitudinal ribs the effect
of which is to centre, or approximately centre, or even if desired to throw out
of the centre to a certain extent, the core relatively to the vaporizing chamber;
these ribs have the further object of facilitating the expulsion of foreign matters
which would form an obstacle to the current of steam in the vaporizing space
or chamber by giving to this mandrel mechanically and externally a rotary or
longitudinal movement, or a combination of longitudinal and rotary movements
which movements may be continuous or intermittent, and automatic or not.
The drawing shows an arrangement for imparting a rotary movement by means
of a worm wheel, but it can be produced by means of a crank handle or by an
arrangement, of levers, gearing &c. worked by hand; or the movement can be
obtained from any central source of power or from a special motor.
This arrange-
ment requires at the joints the employment of a stuffing box i for the passage of
the end of the mandrel 7.
Figure 38 represents three generator elements combined in a plate or block
formed of cast steel or cast iron which constitutes the jacket of the vaporizing
tubes. The element has the peculiarity that its core is without a screw and has
simply at the two ends or at one or more points of its length a series of projections
to centre or approximately centre it in its place. In the element in the metal
forming the jacket is cast around a tube of steel forming a resisting body in which
is lodged the copper tube containing the fluid. The mandrel is shown with a
conical body and with a helix thereon. The element is a combination of the
mand rel shown in Figure 36 with a vaporizing chamber and a jacket such as I
have just described. The different elements of this generator can be combined or
grouped according to requirement.
The last portions of a generator have special need for a mandrel with a helix
thereon, because the rotary movement imparted to the fluid will on account of
the centrifugal force throw against the heated sides all the small drops which
are drawn by the fluid, but this arrangement is not absolutely necessary.
The stuffing box joints shown in Figure 37 may be at each of the ends of
the generator element, and the mandrel or
core may have points of attachment
at each of its ends. The joint boxes may be formed independent of the orifices
necessary for the circulation, or with supplementary communications with the
object of facilitating or modifying the course of the circulation. These are simple
variations and not new arrangements.

page_text: I can employ for the feed of the liquid at a, Figure 36, an apparatus for
reducing it to spray so as to further hasten the vaporization.
I can also employ in the same generator elements of different construction and
joints or connections of different forms according to the position and the conditions
in which the generator has to be employed. The cores or mandrels themselves
may be of different forms; they may be entirely smooth, or smooth at one part of their
length and have a helix or ribs of various forms at other parts of their length.
The vaporizing channels or chambers formed by these ribs may be conical so as
to facilitate the expulsion of the obstacles towards the wider sections.
As I have already stated a generator can be formed of generator clements of
various kinds. One part of the generator may be formed of separate detached
tubes, another part be composed of jacketted tubes connected by several tubes or
plates, and these plates may form partitions for directing the products of
combustion &c.
Figures 39, 40 and 41 show another arrangement of generator element in which
the vaporizing tubes are closed by double boxes held by a single bolt and
allowing of the mandrels or cores M being withdrawn for cleaning these
mandrels have a progressive helix they are conical so that the space,
the tube and the base of the helix increases to give a larger passage to the steam
in proportion to the increase of its temperature.
between
Figures 42 to 46 show various arrangements of mandrels or cores with helices
or longitudinal ribs having continuous or interrupted striations which constitute
stops for the water and cause it to follow the helices or the longitudinal ribs.
Figure 47 shows a mandrel or core with a broken or interrupted helix so as to
form a kind of chamber for the deposit of calcareous matters and facilitate the
rupture or breaking up of these calcareous deposits and the cleansing of the tubes.
Figures 48 and 49 show mandrels or cores without a helix but with projections
in greater or less number of various forms and dimensions and placed cither longi-
tudinally or transversely in relation to the axis of the core.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
1. In apparatus for the very rapid generation of steam or vaporization of liquids,
generator or vaporizing elements having a very restricted and positive but non-
capillary vaporizing space, substantially as and for the purpose set forth.
2. In the construction of apparatus for generating steam or vaporizing liquids,
plates or blocks having holes therein to form external tubes, these tubes receiving
cores or mandrels having a helix, cast therewith to constitute with the outer tube
a non-capillary vaporizing space, substantially as hereinbefore described with
reference to Figures 1 to 6 of the annexed drawings.
3. In the construction of apparatus for generating steam or vaporizing liquids,
plates with grooves therein to receive a tube having a non-capillary vaporizing
space, substantially as hereinbefore described with reference to Figures 7 to 10.
4. In the construction of apparatus for generating steam or vaporizing liquids,
tubes having one or more linings to protect them against oxidation, the said tubes
receiving cores or mandrels to form a non-capillary vaporizing space or chamber
by means of a helicoidal groove, substantially as hereinbefore described with
reference to Figures 11 to 15.
5. In the construction of apparatus for generating steam or vaporizing liquids,
outer tubes of cast iron strengthened by a tube, band or wire of steel or wrought
iron placed in the interior of the cast iron mass at the time of casting, the said cast
iron tubes receiving a core or mandrel to form a non-capillary vaporizing chamber,
substantially as hereinbefore described with reference to Figure 139unter.
6. In the construction of apparatus for generating steam or vaporizing liquids,
tubes with gills and embedded in a sheath likewise having gills, the said tubes
receiving an inner tube to form a non-capillary vaporizing space or chamber by

page_text: means of a helicoidal groove, this inner tube being covered with a jacket to
preserve it from oxidation substantially as hereinbefore described with reference
to Figures 16 and 17.
7. In the construction of apparatus for generating steam or vaporizing liquids,
two concentric tubes, the outer tube having gills and forming with the second an
undulating non-capillary vaporizing space or chamber, substantially as hereinbefore
described with reference to Figure 18.
8. In the construction of apparatus for generating steam or vaporizing liquids,
external tubes with gills receiving inner tubes to form a non-capillary vaporizing
space or chamber by means of a helicoidal groove, the said inner tube being cast
with a core which remains therein substantially as herein before described with
reference to Figures 19 and 20.
9. In the construction of apparatus for generating steam or vaporizing liquids,
copper tubes formed of strips and covered with thinner strips which are wound
thercon in sufficient thickness to obtain a solid and resisting tube adapted for the
arrangements described with reference to Figures 7 and 8, substantially as herein-
before described with reference to Figures 21 to 26.
10. In the construction of apparatus for generating steam or vaporizing liquids,
tubes receiving an inner core or mandrel to form a non-capillary vaporizing space
or chamber by means of studs or projections affixed to or cast with the core,
substantially as herein before described with reference to Figures 27 and 28.
11. In the construction of apparatus for generating steam or vaporizing liquids,
tubes receiving an inner core or mandrel to form a non-capillary vaporizing space
or chamber by means of a wire rolled spirally thereon, substantially as hereinbefore
described with reference to Figures 29, 30 and 31.
12. In the construction of apparatus of the kind herein referred to for generating
steam or vaporizing liquids, flattened copper tubes in which the small sides are
strengthened so as to offer a resistance equal to that of the long sides, substantially
as hereinbefore described with reference to Figures 32 and 33.
13. In the construction of apparatus for generating steam or vaporizing liquids,
plates having a groove to receive a non-capillary vaporizing tube, the ends of this
tube, as well as the central bend, being supported by cast iron pieces connected to
the body of the generator element by means of dowels forming guides or slides in
order to allow of its dilatation while avoiding all wear or strain from the weight of
the said cast iron pieces, substantially as hereinbefore described with reference
to Figures 34 and 35.
14. In the construction of apparatus of the kind herein referred to for generating
steam or vaporizing liquids, generator elements either separate or grouped and
connected by joint boxes which have receptacles to retain foreign matters, the said
generator elements being formed of tubes which receive a mandrel or core having a
helix or longitudinal ribs or simple projections, substantially as hereinbefore
described with reference to Figures 36, 37 and 38.
15. In the construction of apparatus of the kind herein referred to for generating
steam or vaporizing liquids, tubes connected by joint boxes which can be readily
dismounted to allow of the withdrawal of the cores or mandrels for cleaning, the
said cores comprising a progressive helix and being conical so as to allow a larger
passage for the steam in proportion to its increase of temperature, substantially as
hereinbefore described with reference to Figures 39, 40 and 41.
16. In the construction of apparatus of the kind herein referred to for generating
steam or vaporizing liquids, tubes containing a core or mandrel having a helix or
longitudinal ribs with continuous or interrupted striations which constitute stops
for the water, substantially as and for the purpose herein before described with
reference to Figures 42 to 46.
17. In the construction of apparatus of the kind herein referred to for generating
steam or vaporizing liquids, tubes containing a core or mandrel having a broken
helix to form deposit chambers for calcareous matters, substantially as hereinbefore
described with reference to Figure 47.

page_text: 18. In the construction of apparatus of the kind herein referred to for generating
steam or vaporizing liquids, tubes containing a core or mandrel having a greater or
less number of projections or contacts of suitable forms and dimensions and arranged
in suitable manner on the core, substantially as hereinbefore described with reference
to Figures 48 and 49.
T
l Jan of Amil 1901
J. C. MEWBURN,
55 & 56, Chancery Lane, London, Patent Agent.