Improvements in Apparatus for Circulating Water in Steam Boilers.
Year: 1895

page_text: Date of Application, 29th Jan., 1895--Accepted, 16th Mar., 1895
COMPLETE SPECIFICATION.
Improvements in Apparatus for Circulating Water in Steam Boilers.
I, WILLIAM GLASS WRENCH, of 27 Oswald 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 :-
The object of this invention is to promote the better constant circulation of the
water in all classes of steam boilers, by means of an apparatus in the shape of a
dispersive nozzle which shall form the terminal extremity of the feed pipe within
the boiler, and through which the inflowing feed water shall pass and issue directly
therefrom, as an annular divergent current, thereby presenting not only one but
two extended conical surfaces to frictional contact with the boiler water which
according to this invention, are assumed, to possess a compound or two-fold
circulative action in consequence; in this way that while its large exterior surface
is promoting by displacement and friction, an inductive circulation of the water
surrounding it, directly from the mouth of the nozzle towards the water level, or
in any other required direction, its interior surface is similarly active upon the
volume comprised in the area within its circle, by which means a vortex is created
at the apex of this water cone, aud therefore a central or core induction towards it
which is fed by a pipe leading from the bottom of the boiler and which passes
centrally up through and terminates in the throat of the nozzle, and so torms
thereby, the annular orifice through which the feed water is discharged into and
throughout the boiler, dragging as it were, and diffusing in the same direction, a
slug of water from the bottom of the boiler, at every stroke of the feed pump.
In the accompanying drawings which illustrate the invention
Figure 1 is a vertical section and Figure 2 is a plan of a modification of the
nozzle which is placed within the boiler and through which the feed water is
discharged so as to cause circulation of the boiler water.
Figures 3 and 4 are vertical sections of other modifications of circulating nozzle.
Figure 5 is sectional outline of a marine type of boiler showing the water
circulator applied at various points.
Figures 6 and 7 are vertical and horizontal sections in outline of a vertical boiler
to which a modification of the water circulator is shown applied and
Figures 8 and 9 are views of details hereinafter referred to.
In its several forms the nozzle is attached by the flange A within the boiler shell
at any convenient point over the feed water inlet pipe which is connected so that
the feed water enters by the passage B and is discharged through the annular
outlet B¹ of the nozzle thereby creating a suction through the central passage C
to which is connected a pipe D extending downwards to the lower part of the
boiler. From that point the water is drawn at each pulsation of the feed pump
or constantly, when a continuous feeding apparatus such as an injector is used and
it is discharged as a central core jet through the passage C whilst the inlet water
around the annular jet of feed water issuing from the passage B also induces a flow
of the boiler water surrounding it.
As shown at Figures 1 and 2 the energy in the flow of the feed water may be
utilized to turn by impingement thereon, a vaned wheel E placed across the area
of discharge and journaled on brackets F, F, while connected with such wheel E
upon the same axis is an Archimedean or lifting screw G which passes into and
rotates within the central passage or suction pipe C and lifts a quantity of water
at each revolution or part thereof.

page_text: During the process of raising steam a steam jet as at H Figure 5 from an
extraneous source may be applied through this apparatus to promote circulation
and equal heating by blowing it into the lower end of the suction pipe D towards
the nozzle. For this purpose I prefer to employ a hollow bulb upon the end of the
suction pipe D, as indicated in section at Figure 8, from which a thin circular web
of steam can be sent into the pipe from an annular opening I. Either of the
nozzle flanges may be angled or curved to suit the boiler shell or end as required.
Instead of having a plain surface the walls of the annular orifice B¹ of the nozzle
may be fluted spirally or axially as desired as shown in section Fig. 9, or as
indicated at Figure 4 the discharge lips of the nozzle may be recurved inwards
towards the axis as a flange which may be slotted or otherwise perforated for the
further breaking up of the discharge stream into a number of small separate jets.
The internal or suction pipe D may either pass axially through the nozzle as
indicated at Figure 1 or be elbowed towards its side as indicated at Figure 3 in
which latter case it may be pierced at the elbow as shown at d and a jet of the feed
admitted into it as an additional inductive medium. The nozzle is by preference
formed as an elongated spheroid or pear-shaped the discharge end being further
prolonged into a hell or trumpet mouth.
The functions of the passages B and C in this dispersive nozzle are inter-
changeable, ie. the feed water may be injected through the passage C and the
boiler water drawn through the passage B.
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 I
claim is :-
1. A dispersive nozzle for use in causing circulation of water in steam boilers by.
means of the injected feed water and in which the functions of the feed and boiler
water passages are interchangeable substantially as herein described with reference
to the drawings annexed.
2. The improved boiler water circulating apparatus consisting of a dispersive
nozzle adapted for attachment to the boiler shell and through which the feed water
is directed in the form of an annular jet and having a central suction pipe or
passage arranged to draw water by induction from the lower part of the boiler
substantially as described.
3. In combination with a dispersive nozzle for circulating boiler water by means.
of the feed water a vaned wheel fitted over the discharge orifice and connected to
a lifting screw in the suction pipe substantially as described.
4. In boiler water circulating apparatus a suction pipe formed with a hollow bulb
at its lower end having a narrow annular opening into the said pipe and through
which a thin circular web of steam is directed substantially as described.
Dated this 28th day of January 1895.
WALLACE FAIRWEATHER,
Chartered Patent Agent,
62, St. Vincent Street, Glasgow, Agent for the Applicant.