Improvements in Steam Generators.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
Improvements in Steam Generators.
1, BENJAMIN JOSEPH BARNARD MILLS, of 23, Southampton Buildings, in the
County of London, Patent Agent, do hereby declare the nature of this invention
(a communication to me from Charles Altmann, of 18, Rue de la Pyramide,
Lyons, in the Republic of France, Engineer) to be as follows:--
The steam generator forming the subject of the present invention belongs to
that class of generators having narrow channels. It is characterized by a special
mode of construction, uniting a large heating surface with small space and
reducing to a minimum the number of joints and unions, so as to afford ready
access to the interior channels.
The accompanying drawings represent the arrangement adopted for this
purpose.
Fig. 1 is a vertical section through the axis of the generator.
Fig. 2 is a plan view showing half in horizontal section.
The generator consists essentially of two cylindrical metallic envelopes a and b
placed the one within the other and leaving between them a very narrow space
forming a circular channel c.
Deep horizontal channels d, d, formed in the interior face of the envelope a
and in the exterior face of the envelope b open into this circular channel c and
form with it a space having very extended surface in which the water can cir-
culate and be vaporized without passing to the spheroidal state.
The union of these two envelopes a and b is effected by means of two rings g, f
closing the circular channel at the top and bottom and secured by means of
screws e, e, screwed into the thickness of the envelopes protected from the direct
action of the fire. The generator thus formed is submitted to the action of the
furnace which may consume, coal, gas or oil and will be arranged to heat simul-
taneously or successively the exposed surfaces of the envelopes. The steam
generator may, in some cases, be surrounded with a casing of refractory material
or with an annular reservoir within which the feed water may be heated before
being introduced into the steam generator.
The water which is forced by a pump enters the steam generator by a tube h
arranged at the lower part thereof and is vaporized whilst rising within the
grooves.
The steam is collected at the upper part at two opposite points of the circum-
ference by a collector to which may be attached when desired a superheater
entering the furnace. This superheater is formed of a hollow cylinder pro-
vided on the interior surface with grooves i, i, wider than those in the steam
generating part of the apparatus and in the centre of which is arranged the tube
through which the steam passes away. The steam collected by the collector
descends through the tube is superheated in the grooves i and finally passes by
the tube to the place where it is to be employed.
If the envelopes a and b having a certain height were unequally heated, the
D017

page_text: inconvenience of their unequal expansion could be avoided by forming the lower
washer Fig. 3 by means of a diaphragm m of flexible metal held by two separate
rings f, f.
The height and diameter of the envelopes a and b depend upon the quantity of
steam to be generated and the kind of heating means employed but the width
of the channel c and of the grooves d will never exceed the limit beyond which
would be produced the spheroidal state.
Dated this 9th day of August 1899.
1, BENJAMIN JOSEPH BARNARD MILLS, of 23, Southampton Buildings, in the
County of London, Patent Agent, do hereby declare the nature of this invention
(a communication to me from Charles Altmann, of 18, Rue de la Pyramide,
Lyons, in the Republic of France, Engineer), and in what manner the same is to
be performed to be particularly described and ascertained in and by the follow-
ing statement:-
The present invention has for its object a steam generator belonging to that
class of rapidly evaporating generators having narrow circulation channels,
characterized by a large heating surface in a small space and reducing to the
minimum the number of joints and unions, so as to permit the interior channels
to be readily cleaned.
In the accompanying drawings which are shown simply by way of example
Fig. 1 is a vertical section passing through the axis of the generator.
Fig. 2 is a plan view of Fig. 1 showing half in horizontal section.
Fig. 3 represents a modification of a union of the constituent parts of the
generator.
This generator comprises two concentric circular metallic envelopes or casings a
and 6 placed one within the other and leaving between them a very small
channel c; several deep and narrow horizontal channels are formed in the
interior face of the envelope or casing a, in the exterior of the envelope or
casing and opening into the channel e forming with it a space with very large
heating surface. These two envelopes or casings are united by means of two
rings g and closing the circular channel c at the top and bottom and secured by
means of screws e screwed into the thickness of the metal and protected from
the direct action of the fire.
At the upper part of the space c is a collector k which may when required be
fixed on a superheater entering the furnace.
This superheater is formed of a hollow cylinder j provided on the interior sur-
face with grooves wider than those of the generator and in the centre of which
is arranged the tube through which the steam passes away. The water is
forced by means of a pump and enters by the tube & into the generator which is
submitted to the action of the furnace which may consume coal, gas or oil and
will be arranged to heat simultaneously or successively the exposed surfaces of
the envelopes.
If these envelopes a and b having a certain height, were unequally heated the
inconvenience of their unequal expansion could be avoided by forming the lower
joint (Fig. 3) by means of a diaphragm m of flexible metal held by two separate
rings f, f

page_text: MODE OF WORKING.
The water entering the generator by the tube is divided by reason of the
narrowness of the space c, brought in contact with the large heating surface
formed by the channels , it vaporizes immediately and enters by means of the
collector into the chamber of the superheater through which it passes from top
to bottom becoming superheated by its contact before entering the tube
conducts it to the place where it is to be employed.
which
The height and the diameter of the envelopes or casings a and b depend upon
the quantity of steam to be generated and the kind of heating means employed
but the width of the channel c and grooves & should never exceed the limit
beyond which the water would assume the spheroïdal state.
The generator may in some cases be surrounded with a casing of refractory
material or with an annular reservoir within which the feed water may be heated
before being introduced into the boiler.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what
I claim is:-
1. In a rapidly evaporating generator the construction of a vaporizing element
by means of two concentric metallic envelopes or casings adjusted the one within
the other and leaving between them along their entire height a very narrow
annular channel, the adjacent faces of these cylindrical envelopes or casings
being formed with narrow and deep grooves, said envelopes or casings being
united by rings conveniently arranged and fixed by means of screws at their
extremities, substantially as herein described and for the purpose stated.
2. In a rapidly evaporating generator the combination of a vaporizing element
constructed of two concentric metallic envelopes or casings formed with annular
grooves, with a collector in communication with the element and a superheater
formed with a cylindrical space having interior circular grooves in the centre of
which is arranged the steam exit pipe, substantially as herein described and for
the purpose stated.
3. In a rapidly evaporating generator the method of assembling the two con-
centric envelopes or casings constituting the vaporizer by means of flexible mem-
branes placed at the extremities of the said envelopes and held in position each-
by two independent rings fixed respectively by means of screws to each of the
envelopes or casings of the vaporizer with the object of permitting unequal
expansion of these envelopes, substantially as herein set forth.
Dated this 24th day of April 1900.
HARRIS & MILLS,
23, Southampton Buildings, London, W.C., Agents.