An Improved Tubulous Steam Generator.
Year: 1894

page_text: Date of Application, 6th Feb., 1894-Accepted, 14th Apr., 1894
COMPLETE DIEUITIVATION.
An Improved Tubulous Steam Generator.
I, CHARLES SCOTT GALLOWAY, of Port Napier in the Provincial District of
Hawkes Bay, in the Colony of New Zealand, 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 :-
My invention consists in an improved tubulous steam generator of the kind in
which water circulates in annular spaces between inner and outer tubes, so arranged
that flame and hot gases (products of combustion) act upon the outer surfaces of
the outer tubes and upon the inner surfaces of the inner tubes so that heat is
imparted to the water circularly within the annular spaces and steam is generated
which passes into a suitable steam collecting chamber or chambers.
according to my invention such a steam generator is constructed and arranged as
illustrated in. and hereinafter described with reference to the accompanying
illustrative drawings whereof
Now
Fig. 1 shows a central longitudinal section of my improved steam generator
with setting;
.
Fig. 2 shews a front elevation; and
Fig. 3 shews a back elevation with soot door removed.
Fig. 4 shows to a larger scale the mode of fixing the tubes and stays in the walls
of the water chambers.
A and B are two water chambers each constructed of plates of suitable material
such as iron or steel pressed or formed to the required shapes flanged and joined
together. In the inner. plates ab and outer plates a' ' are drilled holes corre-
sponding in number and diameter with the number and the external diameter of the
larger or outer tubes C which are of such length as to extend from the inner plate
of the chamber A to the inner plate of the opposite chamber B and to partly enter
into the said holes wherein the ends of the said tubes are expanded and there is
left in the hole of the inner plate at each end of each outer tube C an annular
rebate or recess for the reception of one end of a tubular stay D. The stays Dare
formed with perforations d; each of these stays fits one of the holes in one of the
inner plates and in an opposite hole formed in the outer plate of the same chamber
and the end of the stay that is fixed in the outer plate of the chamber extends only
partly through that plate so that at the outer end of each stay there is left an
annular rebate or recess.
EE are the inner or flue tubes and are made of such a
length as not only to extend from the outer plate of the chamber A to the outer plate
of the chamber B but furthermore to pass through the holes in such plates and to
project about an inch beyond them, the projecting portions having screw threads
formed upon them to receive screw nuts G G.
Over each end of each inner tube when it is placed in position there is passed a
Hanged annular cover H whereof the part of smaller diameter enters the annular
rebate or recess in the hole in the plate; then, on each end one of the before
mentioned nuts G is placed and screwed home against the cover which is thus
caused to bear tightly against the outer plate and form a steam-tight joint.
By combining a set of "double-tubes" with such chambers A B at the respective
ends the circulation of the water is greatly facilitated; the said tubes when fixed
in the manner herein described serve to stay and strengthen the chambers; a also
do the perforated tubular stays DD; and the arrangement is such as to greatly
facilitate the cleaning of the tubes. The mode of setting as illustrated aids in this
respect, as access can readily be gained to the tubes by removing the door I ; and
any matter removed from the tubes being deposited in the smoke box K, can be

page_text: readily removed therefrom by opening the door L. M is a steam and water
chamber; it is connected by pipes N with the front chamber A and by pipes O
with the back chamber B; and may be fitted with any known or suitable kind of
separating device for separating the steam from the water. If desired the pipe O
may be carried up to a point above the water level in the chamber M. My
improved steam generators must of course be provided with the usual and necessary
fittings such as water gauge, safety valve, and blow off cock.
In some cases the tubular stays D may be dispensed with the tubes C then
terminating at each end at the inner plates ab and suitable screwed stays or
distance pieces being inserted at convenient positions between the inner and outer
plates of the vessels A B.
Having now particularly described and ascertained the nature of my invention
and in what manner the same is to be performed I declare that I do not claim
broadly the use of tubes arranged one within another so that products of
combustion can act on the exteriors of the outer tubes and the interiors of the inner
tubes and water can circulate in the annular spaces between the inner and outer
tubes and steam generated can be conveyed to a steam chamber or drum but what
I do claim as my said invention is :-
1. In a steam generator of the kind referred to the hereinabove described
combination and arrangement of water chambers A and B with outer tubes C and
inner tubes E.
2. A steam generator of the kind referred to in the preceding claim wherein the
outer and inner plates of the water chambers A and B have formed therethrough
holes of the external diameter of the outer tubes; the ends of the outer tubes are
expanded in the holes in the inner plates; tubular perforated stays are fixed in the
holes in both plates and the inner tubes are fixed in position by means of flanged
annular covers which close the ends of the annular spaces between the inner and
outer tubes and nuts that are screwed upon the ends of the inner tubes as described
and illustrated.
3. My improved steam generator substantially as described and shewn in the
accompanying drawings.
Dated this 6th don
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