Improvements in and relating to Steam Generators.
Year: 1888

page_text: Date of Application, 29th Nov., 1888
Complete Specification Left, 29th Aug., 1889-Accepted, 5th Oct., 1889
PROVISIONAL SPECIFICATION.
Improvements in and relating to Steam Generators.
1, ROBERT TOBIN of No. 79 Sir John Rogersons Quay, Dublin Engineer, do hereby
declare the nature of this invention to be as follows:-
My Invention has for its object to produce a steam generator which shall possess
among other advantages lightness in construction, economy of fuel, freedom from
priming and absence of all dauger in the event of the cracking or bursting of any of
the tubes.
The improved generator according to my Invention consists of a boiler shell of
ordinary shape and of suitable dimensions, within which are arranged a number of
tubes or pipes of large diameter. Attached centrally at one or both ends within the
above referred to tubes are arranged smaller tubes, open at both ends; the combination
of the series of two tubes forming tubular chambers; over the exterior and interior
surfaces of which chambers the heat from the fire passes, the products of combustion
passing therefrom to a suitable smoke stack.
In the upper portions of the tubular chambers above described are inserted per-
forated tubes exteriorily connected with a water supply, each provided with a suitable
cock or valve.
Each of the tubular chambers is connected, by means of suitable pipes, provided
with cocks or valves, with a steam chest, whence the steam is conveyed by a pipe,
also provided with a cock or valve, to a superheater, and from thence to the
engine.
The action of the improved generator according to my Invention is as follows, that
is to say: The water is ejected in fine spray upon the interior walls of the tubular
chambers where it is instantaneously converted into steam, whence it passes into the
steam chest, and thence to the superheater, where it is again subjected to the influence
of heat before being supplied to the motor, which it reaches in a highly dried
condition.
From the foregoing it will be obvious that "priming" is rendered impossible inas-
much as the water is only supplied in sufficient quantity to allow of its instantaneous
conversion into steam. Any excess of water remaining in the tubular chambers, as also
residual substances or sediment may be drawn off by suitable blow off cocks or valves,
and mud cocks.
'
With a view to reducing the heat without drawing the fire, in the event of any of
the tubular chambers leaking, I provide an enclosed box or chamber at the side of the
boiler, into which, by means of a rack and pinion or equivalent means the fire box is
withdrawn through a trap arranged at the side of the boiler, said trap being actuated
also by a rack and pinion or equivalent device.
By the above described means I am enabled to vary the heat to any desired degree,
or to remove it altogether from the steam generator for the purpose of effecting repairs
to or changing the tubes.
The enclosed box or chamber above referred to for the reception of the fire box and
bars is provided with an auxiliary smoke flue to carry off the products of combustion
when the fire is withdrawn from the generator.
Dated this Twenty ninth day of November 1888.

page_text: COMPLETE SPECIFICATION.
Improvements in and relating to Steam Generators.
I, ROBERT TOBIN of No. 79 Sir John Rogersons Quay, Dublin, Engineer, do hereby
declare the nature of this invention and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement:-
My invention has for its object to produce a steam generator which shall possess
among other advantages lightness in construction, economy in fuel, freedom from
priming and absence of all danger in the event of the cracking or bursting of any of
the tubes.
And in order that my Invention may be thoroughly understood I have appended the
accompanying sheets of drawings.
Figure 1 is a vertical section of a generator constructed in accordance with my
invention, taken along such a line as A B Figure 2.
Figure 2 is an end elevation partly in section of the same construction of
generator.
Figure 3 is a vertical section of an alternate arrangement of part of the generator,
hereinafter referred to.
In these figures similar letters of reference indicate corresponding parts.
The improved generator according to my invention consists of a boiler shell of
ordinary or any other shape and of suitable dimensions, within which are arranged
a number of tubes or pipes A of large diameter. Attached centrally at one or
both ends within the above referred to tubes A are arranged smaller tubes B open
at both ends, the combination of the series of two tubes forming tubular chambers C,
over the exterior and interior surfaces of which chambers the heat from the fire
passes, the products of combustion passing therefrom to a suitable smoke stack or
chimney D. In the upper portion of the tubular chambers C are inserted per-
forated tubes E exteriorily connected with a water supply the pipe to each tube E
being provided with a suitable cock or valve a, for controlling the passage of the
water thereto. The tubes E are stopped or plugged at the end opposite to that
at which the water enters.
pro-
Each of the tubular chambers is connected by means of a suitable pipe F,
vided with a cock or valve 6 to a steam chest G, whence the steam is conveyed
by a pipe H, also provided with a cock or valve c, to a superheater I and from
thence to the engine by the tube or pipe d provided with cock or valve e.
By means of the valves or cocks and "b" each tubular chamber is rendered
independent of the others and the supply of water to its perforated tube may be
cut off thus enabling the generator to continue working when the said perforated
tube is cracked' or damaged.
"
a
The superheater I instead of being outside the boiler shell, as in Figures 1 and 2,
may be included within the same.
The tubular chambers are so supported and situated as to be easily detached and
got at in order to facilitate repairs.
I have shown only three tubular chambers, Figure 2, one of which is omitted
for clearness in Figure 1, but I may employ any suitable number.
The action of the improved generator according to my invention is as follows:
The water is ejected in fine spray upon the interior walls of the tubular chambers C
where it is instantaneously converted into steam whence it passes into the steam
chest and thence to the superheater I, where it is again subjected to the influence
of heat before being supplied to the motor, which it reaches in a highly dried
condition.,
From the foregoing it will be obvious that "priming" is rendered impossible
inasmuch as the water is only supplied in sufficient quantities to allow of its
instantaneous conversion into steam,

page_text: Any excess of water remaining in the tubular chambers, as also residual sub-
stances or sediment, may be drawn off by suitable blow-off cocks or valves and
mud cocks.
With a view to reducing the heat without drawing the fire, in the event of any
of the tubular chambers leaking, I provide an enclosed box or chamber J at the
side of the boiler shell into which by means of a rack K and pinion L or equiva-
lent means the travelling fire grate or furnace M is withdrawn into the enclosed
box or chamber. The pinion L is actuated by means of a ratchet and handle N
and ratchet wheel O keyed on the pinion shaft or by other equivalent means;
such as by a crank handle. The entrance to this chamber is closed by means of
a door or trap, P, which is lifted by means of a rack Q and pinion R or other
device, to allow of the passage of the firegrate or furnace, which is mounted of
four wheels m. The said door or trap is lowered when the fire place or furnace
has been removed into the said enclosed box or chamber.
The interior arrangements of the furnace, such as the firebars, ash-pan, etc.;-may
be of any construction, but the fire-bars are preferably placed at the top, and the
sides of the furnace are of sufficient height to keep the fuel in its place on the
fire-bars.
By the above described means I am enabled to vary the heat to any desired
degree and to remove the fire-or furnace altogether from the steam generator for
the purpose of effecting repairs to or changing the tubes, the side of the box or
chamber J being so fastened as to be readily removeable.
The enclosed box or chamber is provided with an auxiliary smoke flue S to
carry off the products of combustion when the fire is withdrawn from the
generator.
In Figure 1 is shown one arrangement for effecting the heating of the exterior
and interior surfaces of the tubular chambers C. In this arrangement the heat
from the fire rises and circulates round the exterior of the tubes A and passes
out at the upper part of the plate to which the forward ends of the tubes are
attached. At the same time the heat also passes from the fire to the rear ends
of and through the tubes B to the smoke stack or chimney.
. In the alternate arrangement shown in Figure 3 the heat passes from the fire
and circulates round the exterior of the tubes A then passes into the smoke-box T,
from thence into ends of the tubes B, which open into the smoke box T, and
through the tubes B into the smoke stack or chimney.
The rest of the generator, such as the steam chest, superheater, etc.. is omitted
in this figure, though these arrangements would equally apply as in the case of
Figures 1 and 2.
In this arrangement however the auxiliary flue S would pass directly from the
enclosed box or chamber J into the smoke stack or chimney D and would not
have any connection with the smoke box T.
The arrows in both figures show the direction of circulation of the heat.
I do not bind myself to any particular means of or arrangement for heating the
exterior and interior of the tubes forming the tubular chambers as I may con-
siderably vary the arrangements by which it can be effected.
A thermometer may be attached or connected to the said tubular chambers in
order to ascertain their temperature.
I do not bind myself to the exact form of boiler frame or tubes shown, as the
principle of my invention may be applied to other forms.
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 1
claim is :-
First In steam-generators the improved means for spraying in the feed-water and
for effecting its immediate conversion into steam consisting of perforated supply tubes
contained in tabular chambers heated externally and internally, which perforated tubes

page_text: are fed from any suitable external source, substantially as and for the purposes
described with the aid of the accompanying drawings.
Second-The combination of the perforated tubes E connected to a water supply,
the tubular chambers C connected to the steam-chest, both being connected as stated
by pipes provided with valves a and b, by which arrangement each tubular chamber
is rendered independent of the others and the water supply can be cut off from each
perforated tube at will, the superheater I and pipes d, H and valves c, e, substantially
as described herein and illustrated by Figures 1 and 2 of the accompanying drawings.
Third The improved apparatus or means by which the heat can be reduced
without drawing the fire, consisting of the travelling fire grate or furnace M, the
enclosed box or chamber J, and the auxiliary flue S, substantially as described herein
and illustrated by Figures 1 and 2 of the accompanying drawings.
:
Fourth The improved construction of steam generator substantially as described
herein and illustrated by the accompanying drawings.
Dated this 29th day of August 1889
JAMES
STEVENSON,
Gray's Inn Chambers, 20, High Holborn, London, W.C., Agent for Applicant.