Improvements in and connected with Furnaces and Steam Generators.
Year: 1891

page_text: Date of Application, 1st June, 1891
Complete Specification Left, 1st Mar., 1892-Accepted, 7th. May, 1892
PROVISIONAL SPECIFICATION.
Improvements in and connected with Furnaces and Steam
Generators.
I, THOMAS HOSKING of 28 South Castle Street Liverpool, Engineer, do
hereby declare the nature of this invention to be as follows:-
My present invention relates to appliances for utilising some of the waste heat
of steam generators for the purpose of increasing the draught and preventing
smoke, by the agency of steam generated by the said waste heat.
place in the uptake or chimney of the steam generator, an independent
secondary steam generator, preferably of cylindrical form; the axis thereof may
be horizontal or vertical; in the former case I provide free passages for the furnace
gases through the secondary generator by fitting therein open ended cross tubes
preferably vertical and tapered, with their larger diameters downwards; in the
vertical arrangement I prefer to make the secondary generator of annular cross
section and to make the central passage so obtained of taper form and I also fit
vertical open ended tubes passing through the top and bottom walls of the
secondary generator, which afford additional passages for the furnace gases.
I utilise the steam generated in the secondary generator for the purpose of
inducing one or more currents of air and I provide connections whereby the said
air together with the steam may be delivered at will to one or more of the following
places-that is to say-the furnace below the fire bars, the furnace above the bars,
and the flues, uptake or chimney; the air delivered above the fire bars prevents
smoke and that delivered below the bars assists in keeping them cool.
The currents of air are induced in the well known manner by delivering the
steam in the form of a jet or jets in the centre of or annularly round an air pipe
or pipes and the air is preferably taken from the air casing of the chimney or tube
doors as such air is at a considerable temperature.
In a simpler arrangement, the air pipes may be dispensed with and the steam
generated in the secondary generator may be delivered as jets below or above the
fire bars or into the flues, uptake or chimney or to two or more of these places;
where the said jet or jets are delivered into the uptake or chimney I prefer to
deliver them in the tubes or passages of the secondary generator.
Dated this 30th day of May 1891.
SLOAN & LLOYD BARNES,
Castle Chambers, 26, Castle Street, Liverpool,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in and connected with Furnaces and Steam
Generators.
I, THOMAS HOSKING, formerly of 28 South Castle Street, but now of 1 Thomas
Street, South Castle Street, Liverpool, 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 present invention relates to appliances for utilising some of the waste heat
of steam generators for the purpose of increasing the draught and preventing
smoke, by the agency of steam generated by the said waste heat.
In the accompanying drawings which illustrate my invention,

page_text: Fig. I is an end elevation of my invention applied to a marine boiler,
Fig. is a side elevation, the main boiler and part of the apparatus being in
section on the line A, A of Fig. I, and
Fig. III to V are detail views of the secondary steam generator.
Fig. VI shows a plan of the air injectors 10.
Throughout the drawings, similar parts are indicated by the same reference
figures, and in the case of sections, the direction in which they are viewed is
indicated by the small arrows placed adjacent to the letters denoting the plane of
section.
1 is the main boiler, 2 the uptake thereof, in which is fixed the secondary steam
generator 3 the details of the latter are shown in Figs. III to V, Fig. III is an
elevation and Figs. IV and V are transverse sections on the lines B, B, and C, C,
of Fig. I respectively. It will be seen from an inspection of these figures that
the secondary generator illustrated consists of a horizontal cylindrical portion
fitted with a dome, and that a large central flue 4 together with a number of taper
cross tubes 5 are provided to form passages for the furnace gases from the main
boiler and so increase the heating surface of the secondary generator.
The secondary generator 3 is supplied with feed water in the ordinary way, the
connections for which are not shown, and is provided with a pipe and non-return
valve 6 which delivers into the main boiler when the pressure therein is less than
that in the secondary generator and serves as a safety valve; the ordinary boiler
mountings are also fitted, preferably on the ends, which project for this purpose
through the uptake, as shown, but only the water gauge 7 is shown in the drawings.
The steam which operates the air injectors is taken from the top of the dome of
the secondary generator by the pipe 8 which is connected to the air injectors 9 by
the branch pipes 8' and to the air injectors 10 by the branch pipes 8". The air
supply for the injectors is preferably taken from the air casing 15 (where the
temperature is high) by the bell mouthed inlet pipes 11 which lead to the trunk
pipe 12, which is led down through the smoke box and connected to the injectors 9
and 10 by the branch pipes 121 and 12" respectively. The steam supply to the
various air injectors is regulated by the cocks shown so that any one or more may
be operated at pleasure.
The air injectors are of the ordinary construction and consist of a steam
nozzle 13 within an outer nozzle 14 to which the air is led and in which the current
of air and steam is induced; in the injectors 9 this induced current is directed on
to the fire and prevents smoke while in the case of the injectors 10 the current is
directed below the fire bars and so keeps them cool and assists combustion.
shown in Fig. VI, the injectors 10 are widened out horizontally in the form of a
fan so as to deliver the current of air and steam in a thin sheet and distribute it
well below the fire bars.
As
In a simpler form of the apparatus the air pipes may be dispensed with and the
steam generated in the secondary generator may be delivered as jets above or
below the fire bars, or into the flues, uptake or chimney or to two or more of these
places; where the said steam jet or jets is or are delivered into the uptake I
prefer to deliver them into the flue 4 and taper cross tubes 5 of the secondary
generator.
I do not limit myself to the precise construction of the secondary generator as
illustrated and I prefer in some cases to place the latter with its axis vertical, in
this case the cross section is annular, the central passage so obtained being of
taper form the tubes 5 in this construction pass through the annular space of the
generator.
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. The use of a secondary steam generator placed in the flue or uptake of a
1.
11

page_text: draught and preventing smoke by the action of steam jets supplied by the said
secondary steam generator substantially as set forth.
2. The combination of a secondary steam generator placed in the flue or uptake
of a steam boiler and one or more air injectors operated by steam from the said
secondary steam generator for the purpose of increasing draught and preventing
smoke substantially as described and illustrated.
3. The combination and arrangement of parts forming the improved apparatus
for increasing draught and preventing smoke, substantially as described and shown
in the drawings.
Dated this 29th day of February 1892.
SLOAN & LLOYD BARNES,
Castle Chambers, 26, Castle Street, Liverpool,
Agents for the Applicant.