Improvements in Multitubular Boilers.
Year: 1892

page_text: Date of Application, 23rd Aug., 1892-Accepted, 24th Sept., 1892
COMPLETE SPECIFICATION.
Improvements in Multitubular Boilers.
I, BENJAMIN JOSEPH BARNARD MILLS, of 23 Southampton Buildings, in the
County of Middlesex, Patent Agent, do hereby declare the nature of this inven-
tion, (a communication to me from Alphonse Coignet, of Lyons in the Republic of
France, Manufacturing Chemist,) and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following statement,
reference being had to the accompanying drawings and to the figures and letters
marked thereon :--
The boiler forming the subject of the present invention consists essentially of two
superposed reservoirs or collectors, connected together on the one hand by wide
vertical communications, and on the other hand by a multitubular cluster serving
as an evaporator.
According to the various applications, the collectors may contain a larger or
smaller quantity of water, and each of them can be closed by two or several
cylindrical bodies connected together by sufficient communications.
Figures 1, 2 and 3 of the accompanying drawings show the type of boiler having
only a small quantity of water, and which is known as a non-explosible boiler.
Figure 1 represents a longitudinal section.
and
Figure 2, a front view.
Figure 3, a half plan and a half section, drawn on the line 1-2 of Figure 1,
Figures 4, 5 and 6 show the tube couplings.
The lower collector d occupies the lower part of the furnace at the back; it is
connected to the upper collector e placed above by two vertical tubular columns g g,
which serve at the same time as support to the collector e.
The tubular cluster which connects the two collectors consists of similar tubes
inclined alternately in contrary directions and connected together in pairs at each
end, so as to form a series of serpentines in broken line, commencing at the lower
collector and terminating at the upper collector. Each of these serpentines
comprises two vertical and contiguous rows of tubes inclined in contrary directions
in each row, the lower tube a of the first row, being connected at the rear, by a
connection, to the collector d, is coupled at the front, by a box h, to the lower
tube a' of the second row. This latter is similarly coupled at the rear, by a box A',
to the second tube a² of the first row, which, by the box h2, is connected in front
of the second tube a³ of the second row, and so on to the top, where the last tube a³
is connected, by the connection, with the upper collector e.
The boxes are similar to each other; they are arranged as indicated by
Figures 4, 5 and 6. The tubes a a', furnished at their extremities with conical
enlargements, are introduced into two tubes r of like form, the axes of which are
inclined in contrary directions according to the directions taken by the tubes, and
are there held by collars n bearing against the back of the enlargement and
connected to the box by screw pins whose nuts bear against the exterior of the
latter. The communication from one tube to the other is effected through the
interior of the box.
The connections i, which connect the serpentines to the boilers d and e, are
arranged in like manner, except that they receive only one tube and that they
carry a flanged tube to fix them to the boilers..
The collars n, which unite the tubes to the boxes h and to the connections ii',
are of flat iron and of rectangular form, so that their juxtaposition forms, at the
extremities of the tubular cluster, two walls nn, Figure 1, which limit the

page_text: heating chamber to the free part of the tube, leaving outside the joints, screw pins
and nuts.
At the middle of the length of the tubes are fixed, with capability of expansion,
other rectangular collars, whose juxtaposition forms another wall m m separating
the furnace F from the return flue; these collars also strengthen the tubes at their
centre.
The grate being placed at the front at G, the flames follow the course indicated
by the arrows, twice traversing the tubular cluster, then they are directed to the
chimney by the flue p, after having traversed another tubular cluster transverse
to the first, serving to superheat and dry the steam and to heat the feed water.
The upper row or rows of this cluster are formed of large tubes A A connected
at the extremities by communication boxes similar to those represented at
Figures 4 to 6, so as to form a horizontal serpentine. The steam conducted by the
tube B into the steam chamber f, traverses this serpentine, where it is dried and
superheated before being conducted to the motors. The lower tubes c c, similarly
connected together by boxes H Figure 3, form a second serpentine traversed by
the feed water, which, when it arrives at D, leaves by the tube E, which conducts
it to the lower boiler or collector d.
There results from these arrangements a very active circulation of the water,
which, on leaving the collector d, rises through the tubular cluster into the upper
collector e, whilst the water from this latter again descends by large vertical
conduit 99 into the lower collector.
These two conduits, of which one only may suffice for the circulation, are above
all useful for marine purposes in which the boiler continues to work normally, even
under great inclination.
At the two ends of the boiler, the joints of the tubes are enclosed by doors P P
which can be opened to examine or repair a joint or to change or clean the tubes.
It will be remarked that the furnace being placed below the free part of the
tubes, nothing can interfere with the expansions which may be produced.
.
All the tubes being exactly alike, as also the coupling boxes, provision can be
made for any accident by means of a small number of exchangeable parts.
It will be well understood that, according to the applications, the masonry
furnace can be replaced by a metallic casing furnished or not with refractory bricks
or materials.
When it is desired to have a large volume of water, in lieu of increasing the
volume of the collectors, it is preferable to connect with them supplemental boilers,
as represented at Figures 7 and 8.
These supplemental boilers d'e' are placed parallel to the first d and e and are,
like them, in communication by two tubular columns g¹ g'. The two upper boilers
communicate with each other by large tubes A. A and with the steam chamber f
by tubes s 8. The two lower boilers also communicate with each other by
tubes A' A¹
The lower boiler d', which has taken the place previously occupied by serpentine
feed water heater, serves also for the same use, that is to say, it receives the feed
water, which is delivered at a high temperature, into the lower collector d. This
apparatus presents all the advantages of that above described, both for working and
maintenance.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed declare that what 1
claim is:
1. A boiler composed of two collectors having one or several superposed bodies
communicating with each other on the one hand by tubular columns g g', serving as
supports for the upper collector, and on the other hand by a tubular cluster, serving
as evaporator and forming a series of vertical serpentines whose joints, at the front
and at the rear, form, by their juxtaposition, the walls nn limiting the heating
chamber to the free part of the tubes, one or several similar partitions m being

page_text: capable of establishment along the length of the cluster by means of rectangular
collars carried by the tubes, substantially as herein shown and described.
2. In the boiler above described, the combination of tubes a a¹ having conical
enlargements connected together in pairs by boxes having inclined tubes, so
as to form serpentines capable of being readily dismounted and whose parts are all
similar and interchangeable, substantially as herein shown and described.
Dated this 23rd day of August 1892.
B. J. B. MILLS
By Harris & Mills,
23, Southampton Buildings, London, W.C., Agents.