Improvements in Steam Generators.
Year: 1894

page_text: Date of Application, 22nd Mar., 1894
Complete Specification Left, 21st Jan., 1895-Accepted, 23rd Feb., 1895
PROVISIONAL SPECIFICATION.
Improvements in Steam Generators.
I, JOHN THOM, of 93 Hope Street, Glasgow, in the County of Lanark,
Consulting Engineer, do hereby declare the nature of this invention to be as
follows:-
This invention has reference to steam generators having upright or inclined
tubes through which water is circulated, and extending between and connecting
lower and upper tubes or vessels horizontally disposed, the shells of which act as or
serve as tube plates in which the ends of the tubes are fastened; and it has for
its object to provide improved constructions in this kind of generator by which the
practical utility, constructive characteristics, and efficiency generally, shall be
improved over those at present in use.
According to this invention, in a steam generator of the kind above referred to,
there is combined vertical or upright or inclined tubes through which water passes,
arranged in nests or rows at the sides, or sides and middle, and an upper hori-
zontally arranged vessel for containing water and steam space, and having horizontal
tubes running through it, through which the fire gases after passing from the
furnace (which is disposed between the outer rows or nests of tubes) pass, the upper
ends of these tubes being fastened in the shell of this vessel, and the opposite ends
to the lower vessels.
Under this invention I also so arrange or dispose the upright or inclined water
tubes, and the fire tubes in the upper vessel, that a space or spaces is or are left
between said fire tubes by which the water tubes can be drawn or placed in position,
and also cleaned. And further, this vessel is made, and the arrangement so
employed, that the said tubes can be drawn or placed in position from within same.
Or, suitable detachable doors may be provided above, in the shell of the upper
vessel, through which said tubes can be passed.
In some cases, I use tubes larger and stronger than the upright and inclined
water tubes between the upper vessel and lower horizontal tubes, through which
a down current of water may pass, and by which support is given to the upper
vessel.
The lower horizontal tubes or vessels may be two or more in number, and
running the whole length of the boiler; and may further, in some cases, have a
tube or tubes say at the back part of the boiler between them and connected with
them, and having vertical tubes connecting it or them with the upright vessel. Or,
in another case, the side tubes may not be continuous, and spaced apart at different
distances, those at the front being the wider apart. In the space between the outer
tubes at the front end, and the upright or inclined water tubes at this part, the
fire bars are disposed.
In action, the fire gases from the furnace pass to the back of the steam generator,
to a combustion chamber there disposed (which may be formed of brickwork, or of
upright tubes, or both), and thence through the fire-tubes in the upper water
vessel back to the front of same, where a suitable uptake or smoke box will be
provided.
The sides and front of the furnace may be enclosed with a suitable casing.
These improvements may be employed in and adapted to steam generators
fired at one end, and also those fired at both ends, or at other parts, and it

page_text: may be carried out in different ways without departing from the main characteristics
thereof.
Dated this 21st day of March 1894.
CHEESBROUGH & ROYSTON, Fels. Chart. Inst. P.A.,
15, Water Street, Liverpool, Applicant's Patent Agents.
Improvements in Steam Generators.
I, JOHN THOм, of 93 Hope Street, Glasgow, in the County of Lanark,
Consulting 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 has reference to steam generators having upright or incline:
tubes through which water is circulated, and extending between and connecting
lower and upper tubes or vessels horizontally disposed, the shells of which act or
serve as tube plates in which the ends of the tubes are fastened; and it has
for its object to provide improved constructions in this kind of generator by which
the practical utility, constructive characteristics, and efficiency generally, shall be
improved over those at present in use.
According to this invention, in a steam generator of the kind above referred to,
there is combined vertical or upright or inclined tubes through which water passes,
arranged in nests or rows at the sides, or sides and middle, and an upper hori-
zontally arranged vessel for containing water and steam space, and having
horizontal tubes running through it, through which the fire gases after passing
from the furnace (which is disposed between the outer rows or nests of tubes) pass,
the upper ends of these tubes being fastened in the shell of this vessel, and the
opposite ends in the lower vessels.
Under this invention I also so arrange or dispose the upright or inclined water
tubes, and the fire tubes in the upper vessel, that a space or spaces is or are left
between said fire tubes by which the water tubes can be drawn or placed in
position, and also cleaned. And further, this vessel is made, and the arrangement
S employed, that the said tubes can be drawn or placed in position from within
same. Or, suitable detachable doors may be provided above, in the shell of the
upper vessel, through which said tubes can be parsed.
In some cases, I use tubes larger and stronger than the upright and inclined
water tubes between the upper vessel and lower horizontal tubes, through which
a down current of water may pass, and by which support is given to the upper
vessel.
The lower horizontal tules or vessels may be two or more in number, and
running the whole length of the boiler; and the boiler may further, in some cases,
have a tube or tubes say at the back part thereof, between them, and connected
with them, and having vertical tubes connecting it or them with the upright vessel.
Or in another case, the side tubes may not be continuous, and spaced apart at
different distances, those at the front being the wider apart. In the space between
the outer tubes at the front end, and the upright or inclined water tubes at this
part, the fire bars are disposed.
In action, the fire gases from the furnace pass to the back of the steam generator,
to a combustion chamber there disposed (which may be formed of brickwork, or
of tubes, or both), and thence through the fire-tubes in the upper water vessel
back to the front of same, where a suitable uptake or smoke box will be
provided.
The sides and front of the furnace may be enclosed with a suitable casing.
These improvements may be employed in and adapted to steam generators fired

page_text: at one end, and also those fired at both ends, or at other parts, and it may be
carried out in different ways without departing from the main characteristics
thereof.
Drawings illustrating this invention are hereto annexed, of these
Figure 1 is a longitudinal sectional elevation, and Figure 2 a cross section of one
modification.
Figure 3 is a longitudinal sectional elevation, and Figure 4 a cross section,
shewing another modification. And
Figures 5 and 6 arc, respectively, longitudinal sectional elevation, and cross
section, shewing a third modification.
Referring in the first instance to Figures 1 and 2, a is an upper vessel, having
tubes therein running between and fastened to the end tube plates a', and
constituting a combined water and steam vessel; c are lower side water vessels
lying parallel with a; and d are upwardly arranged inclined tubes running between
the vessels and a, in which their lower and upper ends are fastened, respectively.
The tubes d have water circulating through them, and are subjected externally to
the action of fire gases, while the tubes of the vessel a have passed through them
the gases of combustion after they have left the region of the tubes d, and have
water c.rculating over them externally.
"
is a vessel, similar to e, disposed between the said vessels c, it being connected
with them by the tubes 2; and d' are vertical tubes running between and connected
with the vessel c¹ and a, the position of these parts in this arrangement, is, as will
be seen, beyond the end of the grate or grate bars e.
fare large tubes connecting the vessel a with the vessels c, say at both ends, and
serving as circulating pipes conveying the return or down current of water from a
They also serve as supports or struts to the vessel a, and a means of making a
firm connection of the said vessels.
to c.
The vessel a is made of a somewhat larger diameter than the length of the
tubes and (as for instance, if the tubes or be say 6 ft. 6 in. long, the
diameter of the vessel a may be say 7 ft. 6 in.), and these tubes are so arranged in
relation to the vessel a, and the tubes are so arranged in that vessel, that the
tubes dor d' can be introduced into their proper place and fastened in position, or
withdrawn, from within the vessel a; that is to say, at the part of the vessel a
adjacent or opposite to the part of the shell to which the ends of the tubes d or d¹
are fastened, no horizontal tubes exist in the vessel a, a path or space being left
through or by means of which the said introduction or withdrawal of the tubes
can be made. By this arrangement also the inside of the tubes can be easily
cleaned or scaled, as it permits of a scaling tool being passed into and down them
from the vessel a.
The parts described above will be suitably cased in any known suitable way.
The combustion chamber at the back is formed by a wall i, the roof of which is
arranged just above the ends of the tube b.
In work, the fire gases from the grate e would act first upon the tubes d and d²,
and then pass by way of the combustion chamber into the tubes of the vessel a,
through which they would pass. After the gases leave these tubes they are carried
away from the generator by the smoke uptake provided with the usual door or
doors for cleaning the tubes, etcetera; the steam generator would be thus stoked
and the tubes cleaned and attended to from the same end.
In the modification shewn in Figures 3 and 4, the arrangement and construction
at the back end of the steam generator is different from that shewn and set forth
with reference to Figures 1 and 2; namely, at this end, forming the major or chief
part of the combustion chamber h, there is a vessel 1, a horizontal dome or
vessel m-being an extension on the end of the vessel a, and tubes n running
between and fastened to the vessel and the dome m. The vessel / consists of
a short side part at either side of the vessel a, and a transverse curved part dipping
or bending downwards in the centre; and the tubes are secured in all these parts
of the vessel, viz., both at the sides and transverse part, making an enclosure or

page_text: chamber (h) about the end of the vessel a, whilst brickwork i encloses the space
between the vessel and the end of the vessels e and the grate. The size of the
vessel m is such that the tubes n can be passed into place through it or withdrawn
through it; those, however, which are connected with the transverse part of the
vessel 1, may, in some cases, be adapted to be placed in position or removed through
it, by providing suitable removable covers thereon.
The vessel will be connected with the vessel a by suitable tubes of large
diameter, similar to the tubes f. In some cases the bottom of the vessel m may
be flat and stayed in a similar manner to an ordinary combustion chamber roof.
In other respects than these, the steam generator shewn in these Figures 3 and 4
is substantially or practically the same as that shewn in and set forth with reference
to Figures and 2.
Regarding Figures 5 and 6, the chief characteristics in the modification shewn
in these figures is a boiler consisting of the combination of two (or more) lower
water vessels c, two (or more) tubulous upper vessels a (that is, vessels through
which horizontal tubes exist for conveying the gases through said vessels); and
inclined tubes d connecting the said vessels c and a together, such tubes running
between and connecting one of the lower vessels c on one side or part of the
generator, with a tubulous vessel a on the other side or part. By this arrangement
a steam generator of relatively high power, and compactness of parts or occupying
a small space, is obtained.
In the drawings illustrating this modification, in addition to the arrangement and
combination of parts just specified, the construction and arrangement in connection
with the tubes d and vessel a above described, by which the said tubes can be
introduced or placed and fastened in position, or withdrawn, from within the
vessel a, is shewn; and also the means of effecting the return current between the
upper and lower vessels, namely, the large return pipes f.
The combustion chamber shewn in Figures 5 and 6 comprises a vessel 7 and
tubes n of curved form, running between and fastened to the vessel and the back
tube plate of the vessel a; whilst between the vessel and the grate, a bricklined
wall is provided. In lieu of the bent tubes n, may employ straight tubes as
shewn in dotted lines, the upper ends of which will be fastened to a portion of the
tube plates of the vessels a which are carried out or overhang in the manner shewn
by the dotted lines.
In some cases, several large tubulous vessels u as arranged in Figures 5 and 6
may be used side by side; and they may be made common or connected together
by the downtake or return water circulating pipes of each being connected with
a lower vessel e, which is connected with another of the vessels by the tubes d,
and by connecting the steam spaces at the top.
In some cases the large return tubes f may be dispensed with, and the return of
water to the vessels c carried on automatically through some of the tubes d Ax
regards the form of the tubes d, in some cases curved tubes may be used instead of
straight tubes.
In some cases where convenient, "Field" tubes may be provided or fitted in
the shell of the vessels within the furnace space, whilst up on the upper parts of
the vessels suitable steam receivers or vessels can be fitted.
In some cases, the steam generators according to this invention may be arranged
to be fired at both ends, in which case the vessels a would with advantage be
connected at their back ends over a combustion chamber, such connecting parts
forming the roof thereof, as for instance by the part m as shewn in Figures 3 and 4,
or as indicated by the dotted lines in Figures 5 and 6.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performen, I declare that what I
claim is :-
1. A steam generator consisting substantially of, or comprising, upper and lower
horizontal vessels, tubes connecting said unner and lower vessels through which

page_text: water circulates, and horizontal tubes running through said upper vessel or vessels,
substantially as and for the purposes set forth.
2. In a steam generator of the type or kind herein referred to, the construction
substantially as described by which the inclined or upright tubes between the
lower and upper horizontal water vessels can be placed in position, easily got at
or withdrawn, from within said upper vessel or vessels.
3. A steam generator having two (or more) upper tubulous vessels a, lower
vessels c, and tubes d connecting, and fastened in, said vessels a and c, said parts
being arranged in relation to each other substantially as set forth with reference to
Figures 5 and 6 of the drawings.
4. The steam generator having parts arranged and constructed particularly as
set forth with reference to Figures 1 and 2; Figures 3 and 4; and Figures 5
and 6, respectively, of the drawings.
CHEESBROUGH & ROYSTON, Fels. Chart. Inst. P.A.,
15, Water Street, Liverpool, Applicant's Patent Agents,