Improvements in or connected with Steam Boilers and their Furnaces.
Year: 1891

page_text: Date of Application, 11th May, 1891
Complete Specification Left, 11th Feb., 1892-Accepted, 12th Mar., 1892
PROVISIONAL SPECIFICATION.
Improvements in or connected with Steam Boilers and their
Furnaces.
I, JOHN DEVONSHIRE ELLIS Managing Director of John Brown and Company
Limited Atlas Steel and Iron Works Sheffield in the County of York do hereby
declare the nature of this invention to be as follows:-
My invention consists in the combination of means for supplying to the furnaces
air heated by the waste gases issuing from marine and other steam boilers and of
induced draught obtained by suction as hereinafter explained with reference to a
marine boiler from which its general application will also be understood.
After the hot gases leave the tubes of the boiler they are drawn into a chamber
which may be conveniently situated in front of or above the boilers. This drawing
in of the gases can be effected by means of a fan or other suitable means of
exhausting placed at the opposite end of the said chamber which is traversed by
a series of tubes or passages open to the atmosphere of the stoke-hold. This nest
of tubes or passages (which may be horizontal vertical spiral or of any other
convenient shape or arrangement) will supply the air to the furnaces and tubes at
a rate proportionate to the speed and power of the exhausting appliance which
withdraws the hot gases and this feed air will abstract the heat from the hot waste
gases in its passage through the chamber and down the front of the boiler to the
furnaces.
.
Deted the 11th dan of Mov 1001
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, London, Agents.
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, London, Agents.
COMPLETE SPECIFICATION.
Improvements in or connected with Steam Boilers and their
Furnaces.
I, JOHN DEVONSHIRE ELLIS, Managing Director of John Brown and Company
Limited Atlas Steel and Iron Works, Sheffield in the County of York, 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 of the combination of means for supplying to the fires of
marine and other steam boilers air heated by the waste gases issuing therefrom and
of induced draught obtained by suction whereby after the hot gases leave the tubes
of the boilers they are drawn into a chamber or chambers which may be conveniently
situated either in front of or above the boilers. This drawing-in of the gases, can
be effected by means of a fan or other suitable exhausting device or even by a
chimney of sufficient height. The said chamber or chambers is or are traversed by
a series or nests of tubes or passages open to the atmosphere or the stoke-hold. The
said series or nests of tubes or passages (which may be horizonal vertical spiral or of
any other convenient shape or arrangement) will supply the air to the fire at a
rate proportionate to the power or speed of the exhausting device which withdraws
the hot gases, and this feed air will in its passage through the chamber and down
the front of or around the boiler to the fire become heated by the heat from the
hot waste gases.
And in order that my said invention may be fully understood I shall now proceed
more particularly to describe the same and for that purpose shall refer to the

page_text: several figures on the annexed sheet of drawings the same letters of reference
indicating corresponding parts in all the figures. The drawings represent the
application of the invention to a marine, boiler, and its furnaces but from this its
application to other boilers will also be understood.
Figure 1 is a longitudinal section Figure 2 a transverse section and Figure 3 a
plan (partly in section) of a marine boiler provided with my improvements. The
heated, products of combustion from the furnaces, A pass; through the tubes B
into a chamber C in the front of the boiler D, and pass from this chamber through
openings at c into chambers E arranged horizonally along the opposite sides of the
crown of the boiler. The chambers. E each contain a series or nest of tubes F
which tubes are open at one end to the atmosphere or to the stoke-hold and their
opposite ends communicate with a space G partly surrounding the chamber C and
communicating by passages a and b respectively with the furnaces A above the fuel
and with the ash pit d. The tubes F are heated by the hot gases passing from the
furnaces as herein before described and impart heat to the air passing through the
said tubes so that the said air becomes heated to the required extent before
entering the furnaces whereby the combustion of the fuel is improved.
valves for regulating the admission of the heated air to the furnaces A above
the grate.
e are
In conjunction with the apparatus hereinbefore described I provide in, or in
proximity to, the chimney or uptake H a fan or worm I so as to suck or draw from
the furnaces the heated gases or products of combustion and thereby increase the
draught to any desired extent. In place of the fan or worm I may use jets of
air or of steam in the chimney or a sufficient length of chimney to give the
requisite suction may be used. The full arrows on the drawings shew the direction
of the air through the tubes F to the furnaces A and ashpits d, and the dotted
arrows shew the course of the products of combustion from the furnaces A to
the chimney or uptake H.
I have found that by using, induced draught obtained by suction less injury is
caused to boilers, with high rates of combustion and the tubes are kept cleaner
than in cases where forced draught is used.
I do not restrict myself to the construction and arrangement of the parts shewn
in the drawings as they may be considerably varied without departing from the
nature, of my, invention for example instead of employing, air heating, tubes in two
chambers arranged one on each side of the crown of the boiler they may be
contained in, a single chamber and, the chamber or chambers may be arranged in
any other, suitable position and instead of a number of separate heating tubes. a
single continuous tube, in the form of a coil or otherwise may be employed, and
arranged in, any suitable position so that the heated waste gases, shall act, upon
the tube or tubes to heat the air, which air may be caused to pass, through, the
said tube, or tubes, or the heated gases may be caused to pass through the tube
or tubes and the air to be heated thereby caused to impinge against the exterior
surfaces thereof. The space into which the heated air passes from the heating
tube or tubes before, entering the fire may be made to surround the whole or
any desired portion of the boiler and the whole, or any desired portion, of the
heated air may be admitted at any desired part or parts other than that shewn in
the drawings.
The exhausting device may be of any suitable construction, and may be arranged
in any suitable part.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare,that. what. I
claim is:
1. In, or connected with steam boilers the combination with means for supplying
to the fire air heated by the products of combustion. or waste, gases from the
fire of means for obtaining an induced draught by suction substantially as
hèreinbefore described.

page_text: 2. In, or connected with steam boilers a chamber or chambers containing a
tube or tubes through which chamber or chambers or through which tube or
tubes air is caused to pass and become heated, before entering the fire by the
waste gases issuing from the fire in combination with an exhausting device for
producing induced draught by suction substantially as hereinbefore described.
3. The combination and arrangement of parts substantially as and for the purpose
herein before described and illustrated by the accompanying drawings.
Dated this 11th day of February 1892.
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, London, W.C., Agents.